The UN secretary-general has spoken of the "mass destruction" caused by small weapons, at a conference looking at ways to restrict their use.
Victims of small arms are calling for tighter controls
Kofi Annan said the proliferation of light weapons such as machine guns had spawned a "culture of violence".
He was speaking at a UN conference in New York which is considering ways to tackle the global spread of small arms.
Anti-gun campaigners presented him with a petition calling for tighter controls on the trade in such weapons.
The Control Arms campaign is backed by the inventor of the infamous AK-47 rifle, Mikhail Kalashnikov.
The retired general has blamed a "lack of international control over arms sales" for allowing the weapons he designed to fall into the hands of "aggressors, terrorists and all kinds of criminals".
But major arms exporters including the US, Russia and China have yet to endorse calls for tighter regulations making governments more accountable for the arms they export.
In his opening speech to the Small Arms Review Conference, Mr Annan said: "In a world awash with small arms, a quarter of the estimated four billion [dollar] annual global gun trade is believed to be illicit.
"Small arms are easy to buy, easy to use, easy to transport and easy to conceal.
"Their continued proliferation exacerbates conflict, sparks, refugee flows, undermines the rule of law and spawns a culture of violence and impunity."
The secretary-general stressed the UN's efforts were directed at the spread of illegal weapons.
"Our targets remain unscrupulous arms brokers, corrupt officials, drug trafficking syndicates, criminals and others who bring death and mayhem into our communities," he said.
Before the conference opened, the Control Arms campaign presented its petition containing one million signatures from 160 countries - representing the number of people killed by guns since the last UN conference on small arms in 2001.
The campaign's report, produced by Amnesty International, Oxfam International and the International Action Network on Small Arms said light arms were killing 1,000 people a day.
Eight million guns made every year
800,000 destroyed annually
25% of $4bn annual global small-arms trade is illicit
Guns used in 60-90% of direct-conflict deaths in 2003
6% of suicides and 40% of homicides involve guns
Source: UN Small Arms Review Conference
The report found the AK-47 was the world's most poorly-regulated small arms weapon.
It said 82 countries had them in their state arsenal and 14 nations manufactured them. The rifle fires 600 rounds a minute, is reliable and available for as little as $30 (£16) in some parts of Africa.
In giving his backing to the Control Arms campaign, Mr Kalashnikov said: "When I watch TV and see small arms of the AK family in the hands of bandits, I keep asking myself: how did those people get hold of them?"
The "global principles" that the campaign proposes would be non-binding, but would allow governments to bring violators to account more easily.
The UK has made a similar proposal and has the backing in principle of the US and others.
But US Ambassador to the UN John Bolton made it clear Washington did not want to go beyond a programme adopted five years ago to curb the illicit sale of light weaponry.
"We don't see any need for treaties or agreements coming out of this," he said.