President George W Bush plans to deploy up to 6,000 reserve soldiers of the US National Guard on the border with Mexico, as part of his plan to counter the flow of illegal migrants entering the United States.
Mexicans peer through a fence on the border in Tijuana, Mexico
The president has also spoken of creating a legalised system that would allow foreigners to work temporarily in the US.
Many people, however, including a good part of the president's Republican party, believe Mr Bush should be taking a harder line and criminalising illegal immigrants.
Six people with a stake in the debate give their views.
Click on the links below to read what they have to say.
Congressman Tom Tancredo has campaigned throughout the US in support of tighter border controls and immigration reduction
Americans are rightly outraged by our broken immigration system: there are roughly 12 to 15 million illegal aliens in the US, and hundreds of thousands sneak across our borders each year.
Mexican citizens waiting to cross the border illegally
Our porous borders pose a major national security threat because not all of the illegal aliens are coming to "do the job that no American will do," as President Bush often says. For example, in 2004, the US Border Patrol apprehended Iranians, Syrians, and Iraqis who tried to cross our southern border illegally.
Why are Iranians, Syrians or Iraqis trying to get into the US, travelling a great distance and at a great cost? Certainly, it's not to work at minimum wage jobs.
Illegal immigration also has a negative effect on the US's economic security. It doesn't take a degree in economics to realise that a massive flow of low-skilled labour puts downward pressure on the wages of native-born Americans.
These low-wage workers - who are largely paid off the books and without benefits - meanwhile cost the American taxpayer in terms of social services. Illegal aliens rarely pay taxes, yet they send their children to our schools free of charge, they receive welfare benefits, and they get free medical treatment.
The best solution to our illegal immigration problem is to begin enforcing our laws. That means the federal government needs to get serious about prosecuting employers who lure illegal aliens into the US with jobs. The threat of hefty fines and possible jail time will chasten employers' desire to hire cheap, illegal workers.
We also need to recommit to guarding our borders with more personnel, more technology and more money for physical infrastructure. And, we need to enable local police departments to aid the federal government in finding and deporting illegal aliens.
Over time, as it becomes more difficult to come here illegally, fewer will try. And, as it becomes harder to stay illegally, more will leave over time. That's a workable solution to our broken borders.
Nativo Lopez is national president of Mexican-American Political Association, which campaigns for the Latino community
With a wink and a nod, the United States government essentially allowed millions of people into the country to be employed in vital strategic industries.
These workers produce value and that value is appropriated by business owners. The worker is never remunerated fairly for the value he creates and the immigrant worker creates a value far and above what a native worker creates because he works for a lower wage, does not have paid holidays, a pension plan or sick pay.
They make an incredible economic contribution to the economy. A fair exchange would be a streamlined procedure allowing them to legalise their status.
The current legislation being debated by the Senate, the Hagel-Martinez compromise, would not be satisfactory for the immigrant communities.
The three-tier legalisation procedure includes onerous conditions that would preclude from citizenship the people it is supposed to help.
For example, anyone who has used fraudulent documents is disqualified but in order to obtain employment, a driver's licence or emergency benefit, they would have had to have used false documentation.
Anyone who has been caught for illegal entry, was issued an order to leave and has not done so would be disqualified. That is estimated to be 350,000 people.
There are a number of other provisions that eliminate the right for judicial review and appeal for all immigrants. Instead of strengthening the rights of immigrants, Hagel-Martinez codifies the elimination of those rights.
And the president's militarisation proposal - to send National Guard troops to the border and construct a border wall - essentially constitutes weakening of the rights for all Americans, not just for immigrants.
More appropriate legislation would be as close as possible to the Immigration Reform and Control Act of 1986 - a generally simple, streamlined, not cost-prohibitive procedure that successfully legalised 3.3 million individuals, most of whom have become citizens.
But considering the current composition of the Senate, I am not confident that anything good will come from this Congress.
Mariann S Davies is with the You Don't Speak For Me Coalition, a group made up of US citizens of Hispanic heritage
My parents came to the United States more than 45 years ago from Ecuador. My father served our military in Korea. They are proud, law-abiding citizens who taught us to respect the laws, customs and traditions of our country - America, with the expectation that all people do the same, no matter what their country of origin.
I first noticed the magnitude of the illegal immigration crisis when I worked as a college volunteer during the chaotic implementation of the Immigration and Control Act of 1986 which gave some 3.1 million people legal status. I witnessed chaotic and inconsistent paperwork for people with no documentation. It was a mess, and we now know that much of the information provided by illegal immigrants was fraudulent.
Passions have run high at the many recent marches on illegal immigration
I was amazed that on September 12, 2001, our borders were not secure, and here we are five years later with borders so porous that we now have the huge problem of 12-20 million illegal aliens in our country, many of whom came in since that dreadful day.
Our president and our lawmakers know that we would see a significant reduction in numbers if we enforce the laws we have on the books, cut off the job magnet by punishing employers, and stop the social services and benefits for illegals and their families. Then and only then would we start to see people self-repatriating. Americans need to know the real cost of illegal immigration and tell our lawmakers that enough is enough.
Felipe Aguirre is deputy mayor of Maywood, California. The town, which is 97% Hispanic, is a self-declared sanctuary for 'undocumented' immigrants.
We believe that no human being can be described as illegal.
The town of Maywood has declared itself a "sanctuary" for illegal immigrants
These are people who work hard, pay taxes, buy houses and keep on the right side of the law for fear of being deported - they are part of the fabric of America.
Many have families and have been contributing members of community for years. But the debate is now affecting family units. Many people who do not have the right documents have children who are US citizens. These families need to stay united.
That is why we have seen so many young people taking part in the demonstrations, fighting for the rights of their parents.
These are people pay their taxes through the payroll system, but do not qualify to receive any benefits at the end of the work week. And, while they pay sales taxes and property taxes, they do not qualify for any of the benefits that are associated with this, such as healthcare.
There is a tremendous amount of hypocrisy surrounding the debate. So many businesses are doing well on the back of undocumented workers - from the oranges that are picked in Florida to the tomatoes harvested in Illinois.
Yet, their basic rights, such as the right to a safe workplace and fair treatment, are not protected. Undocumented workers never file complaints for injuries sustained at work for fear of being sacked.
Rich families in Los Angeles employ undocumented nannies to look after their children. They also employ undocumented housekeepers, cleaners and gardeners - many of whom have keys to their houses.
How can we be called criminals when we hold the keys to the houses of some of the richest people in the state?
Chris Simcox is the founder and president of the Minuteman Civil Defense Corps, a volunteer group which monitors US borders for illegal immigrants.
President Bush, the tough-talking cowboy leader of the free world, will deploy 6,000 unarmed National Guard in "support" of US Border Patrol along America's southern frontier with Mexico. This ostensibly will address the threat posed by daily infiltration of American territory by waves of illegal migrants and massive loads of contraband that include billions of dollars of drugs, weapons and exploited human beings.
A Minuteman in the desert on the look out for illegal immigrants
Our National Guard, armed with construction equipment and paper clips, will be placed in the midst of a virtual war zone to build roads and shuffle paper for an outgunned and undermanned federal Border Patrol. President Bush seems to suffer from the notion that the greatest problem facing border agents is insufficient office help, not corrupt Mexican military forces colluding with violent drug cartels and shooting at our people.
The Mexican government also receives the benefit of $50bn sent home annually by illegal aliens.
Law-abiding American citizens have formed a nationwide border watch, the Minuteman Civil Defense Corps, to actually provide support to the Border Patrol. Our ranks include thousands of America's military veterans, former law enforcement officers, schoolteachers, lawyers, doctors, pilots, truck drivers, waitresses and business owners who love our country and will defend her territory, sovereignty and national character.
President Bush's policies will demoralise our National Guard troops, while risking their lives. It will further enshrine our current state of lax border security under the guise of enforcement. The Minutemen categorically reject them as a political ploy which fails to address the crisis of our broken borders.
Lorenzo de la Fuente is the mayor of Nogales, a Mexican border town through which illegal immigrants are deported
Right now we are getting around 500 people a day deported through Nogales [from the US] and this just keeps going up and up every day.
We are right on the border, with about 25,000 population in Nogales in the US and 325,000 to 350,000 people in Nogales in Mexico.
The only thing that separates the two cities is a fence where you can walk across between both countries.
We don't have too many people crossing from Nogales to the US - but in the past eight months to a year most of the deportations from the state of Arizona have come through Nogales. We don't have any say in that.
With more National Guard troops on the border, I think we are going to see a lot more people deported.
At the moment, of those deported, about two-thirds turn round and go straight back to the States. We ship back 25-30% to their states of origin on buses - but we still have between 10% and 15% who stay, and that is a burden.
A lot of the people that are being deported through here are from Central America. They get mixed up with the Mexican people and then end up staying here if they can't get across. There are also between 30 and 40 minors a day.
The state government is helping but we are getting very little from the federal government. They say they don't have enough resources.
We have several shelters here where we give people food, clothing, a room and board for about a week.
But it's a strain financially and also on the services here. All the shelters are full to capacity and we cannot afford new ones.
It's a complex problem. We know the US laws and we have to respect them - but they cannot find people in the US to do these jobs that Mexicans will do.
As long as there is work in the US, people are going to keep on coming and keep on crossing - nothing will hold them back. We have to create more jobs to keep our people here.