Human Rights Watch, an international advocacy group, called on both Russia and Ukraine to stop using the weapons, and urged the U.S. not to supply them. More than 120 countries have signed on to an international treaty banning the weapons, which typically scatter a large number of smaller so-called bomblets over a large area that can kill or maim unwary civilians months or years later. Russia, Ukraine and the U.S. have all to declined to sign the treaty.