( CNN ) -- The United States and Russia were absent Wednesday as representatives from countries from around the world gathered to sign a treaty banning the use of cluster bombs . French troops examine cluster bombs collected after the Lebanon conflict of 2006 . Some 111 countries were due to adopt the Convention on Cluster Munitions at an all-day signing ceremony in Oslo , Norway . But four of the biggest cluster bomb makers -- Russia , China , Israel and the United States , which claims the devices are a vital part of its defense strategy , stayed away . Cluster Munition Coalition activists behind the agreement expressed disappointment at the absence of the big four , but insisted it would n't undermine the treaty as it passes into international law . `` Obviously it 's very disappointing that those countries are n't here , but at the same time , the strong message that this treaty sends will make it very clear to those countries that these are unacceptable weapons and inappropriate in future conflicts , '' CMC Co-Chair Richard Moyes told CNN from Oslo . `` The treaty and the stigma that it builds will make it practically and politically much more difficult for them to use these weapons again in the future , '' Moyes added about the absent countries . `` Many of their partners will no longer be allowed to use these weapons , and clearly recognize these weapons as far too costly in humanitarian terms . '' Cluster munitions , which break apart in flight to scatter hundreds of smaller bomblets , are described by the International Committee of the Red Cross as a `` persistent humanitarian problem . '' Most of a device 's bomblets are meant to explode on impact , but many do not . Credible estimates show the weapons fail between 10 and 40 percent of the time , leaving civilians at risk of harm from unexploded ordnance , the ICRC says . In addition to calling for a total , immediate ban of the weapons , the Oslo accord calls for strong standards to protect those injured . It urges that contaminated areas be cleaned up quickly and weapons immediately destroyed , the CMC said . The agreement requires the destruction of stockpiles of the weapons within eight years , said Thomas Nash , coordinator of the Cluster Munition Coalition . Earlier this year , a U.S. State Department representative called it `` an absolute moral obligation '' to rid a battlefield of unexploded ordnance after battle , but the insists cluster munitions are an important part of its defense strategy that can be regulated post-conflict . During the 34-day war in Lebanon in 2006 , the United Nations estimated that Israel dropped 4 million bomblets , 1 million of which may not have exploded , according to the ICRC . More than 250 civilians and bomb-disposal operators have been killed or injured by them in southern Lebanon since the war ended . Cluster bombs were also used in the 1999 war in Kosovo . In more than 20 countries , according to the ICRC , cluster bombs have created lasting `` no-go '' areas , rendering them as dangerous as minefields . Laos is the most affected country . Millions of bomblets dropped during the Vietnam War continue to kill civilians more than three decades later .
United States , Russia absent from negotiations of cluster bomb ban treaty signing . Currently , Russia , China , India are top four cluster bomb producers . U.S. insists the devices are important part of its defense strategy .