US President George W Bush has urged America to give his new Iraq strategy "a chance to work", in his seventh annual State of the Union address.
Failure in Iraq would have "grievous" consequences, Mr Bush told Congress.
His speech also focused on domestic issues, and he called on political opponents to join him in tackling the US's most profound problems.
Energy policy was near the top of the agenda. Mr Bush called for a 20% cut in petrol consumption by 2017.
But the BBC's James Westhead, in Washington, says that the speech overall offered little new to the president's supporters and even less to his opponents.
This is perhaps a sign of diminishing expectations of the remaining two years of this presidency, our correspondent adds.
"Our country is pursuing a new strategy in Iraq, and I ask you to give it a chance to work," the president told a joint meeting of the House of Representatives and Senate.
He described the "war on terror" as a "generational struggle that will continue long after you and I have turned our duties over to others".
Mr Bush added: "On this day, at this hour, it is still within our power to shape the outcome of this battle. So let us find our resolve, and turn events toward victory."
It was his first State of the Union speech since the Democrats took control of Congress.
Recent opinion polls suggest only one-in-three voters approve of the job the president is doing - making him more unpopular than any other president in the last 50 years, except Richard Nixon just before he resigned.
In a tough Democratic response to the address, Senator Jim Webb said the US needed a "new direction" in Iraq.
"The majority of the nation no longer supports the way this war is being fought; nor does the majority of our military," he said.
Mr Bush said he would ask Congress for $1.6bn (£808m) over the decade to fund research into alternative energy and $2bn in loans for cellulosic ethanol plants.
Reduce petrol consumption by 20% in 10 years
Step up domestic oil production
More money for alternative fuels
"War on Terror"
Increase Army by 92,000 over five years
Create advisory council
Set up Civilian Reserve Corps
Increase spending discipline
Halve number of "earmarks"
"Fix" Social Security and Medicare
But there are no indications that he will impose specific limits on greenhouse gas emissions.
This will dismay not just Democrats, but some Republican-supporting industrialists who want Mr Bush to adopt a comprehensive strategy for tackling climate change, the BBC's Iain Watson in Washington says.
Mr Bush also called for a strengthening of America's energy security - he wants to double the country's Strategic Petroleum Reserve by 2027.
The SPR is an emergency petroleum store with the current capacity to hold up to 727 million barrels of crude oil.
"For too long our nation has been dependent on foreign oil," the president said.
"And this dependence leaves us more vulnerable to hostile regimes, and to terrorists - who could cause huge disruptions of oil shipments... raise the price of oil... and do great harm to our economy."
Mr Bush also addressed the difficulties an estimated 47 million Americans face in obtaining health care, proposing a tax break for the least well-off to make health insurance more affordable.
"We must remember that the best healthcare decisions are made not by government and insurance companies, but by patients and their doctors," Mr Bush said.
But, according to our correspondent, the money is likely to come from taxing those with generous corporate health care schemes, which could risk alienating Republican support.
The president also urged Congress to pass a comprehensive immigration reform bill.
"We cannot fully secure the border unless we take pressure off the border - and that requires a temporary worker programme," he said.
And the president said he would submit plans to eliminate the federal budget deficit within five years.
"What we need to do is impose spending discipline in Washington DC," he said.
But it is on Iraq that members of Mr Bush's Republican party are most sceptical, our correspondent says.
And the Democrats are keen to exploit those divisions.
In the Democrat's response, Sen Webb called for "a policy that takes our soldiers off the streets of Iraq's cities, and a formula that will in short order allow our combat forces to leave Iraq".
Domestically, the senator said America was "drifting apart along class lines" amid an "economic imbalance" in the country.
If the president took the "right kind of action", Sen Webb said Democrats would join him.
"If he does not, we will be showing him the way," he added.