The 92 signatories to the United Nations Convention on Certain Conventional Weapons were expected to approve by Friday a binding protocol on so-called Explosive Remnants of War, after two years of study and 12 months of negotiations.

"It is the first international treaty which requires to clear all unexploded weapons that pose a threat to civilians when the war is over," said India's ambassador for disarmament, Rakesh Sood, who is presiding over the talks.

"With this protocol, states will have a responsibility to clear or assist in such clearance. It will no longer be possible for parties to a conflict to just walk away," he told a news conference in Geneva.

The protocol will enter into force once it is ratified by at least 20 countries, Sood explained, adding that this would mark the first legally-binding treaty on disarmament adopted at the United Nations since the anti-personnel landmines text of 1996.

"It's a divine surprise," said one Western diplomat, noting that Washington had earlier opposed the idea of a compulsory treaty.

The protocol says culprits will have to clear unexploded weapons from foreign territories they control as a result of war.

It notably covers mortar and artillery shells, grenades, rockets, missiles and cluster bombs, which are increasing used by the United States.

Cluster bombs, which the US unleashed in great numbers in Iraq and Afghanistan, are designed to scatter smaller explosive charges which, in theory, detonate when they hit their target, causing horrific injuries.

Experts estimate up to a third of these bomblets, or sub-munitions, do not explode immediately on contact and continue to put innocent lives at risk, notably children, long after a conflict has ended.

In a message to the negotiators, who were meeting in Geneva on Thursday and Friday, UN Secretary General Kofi Annan described the leftovers of war as "sleeping killers which continue to threaten men and women in fields and children at play, endanger the lives of aid workers and hold back reconstruction and development".

Paul Vermeulen, director of Handicap International in Switzerland, said on Thursday tens of millions of unexploded munitions were thought to be scattered across 82 countries.

In France and Belgium explosives from World War I were still being discovered almost every week and the problem was particularly severe in southeast Asian countries like Laos and Cambodia which were attacked by the United States in the 1970s.

"In Cambodia, for every mine found there are nine more unexploded," Vermeulen said.

The International Committee of the Red Cross, which was the initiator of the discussions on unexploded ordnance in 2000, reacted favourably to the news of an imminent agreement on a new protocol.

"In the countries where we have a presence, we are going to have legal means to approach the authorities and ask them to work together with us," said Dominique Loye, a technical advisor in the ICRC's mines and arms unit, adding that the protocol responded "to a great extent" to anxieties about such weapons.

The response was more circumspect from Handicap International, which was one of 80 non-governmental organisations that earlier this month launched a global campaign to ban cluster bombs "until their humanitarian problems have been resolved".

Vermeulen said the treaty was "far too feeble" and contained "too many formulas which enable states to take decisions to suit them".

The text does not commit states to paying for the damage they cause. It simply invites aggressors to record the sites they attack to enable an exchange of information following a conflict.

As for ongoing conflicts, the protocol would "not immediately reduce the impact of war", Vermeulen said.

WAR.WIRE