The Obama administration has never signed on to the international ban on cluster bombs. The U.S. attempted to water down the ban by suggested that manufacture of the bombs should be regulated rather than banned. The U.S. was supported by Russia, China, and Israel all of whom have cluster bombs and have failed to sign on to the ban.
Even the UK which usually supports U.S. policies filed objections to the U.S. proposal. Unlike the U.S. the U.K. has already signed on to the ban. The U.S. said it was deeply disappointed by their failure. The regulations it claimed would have prohibited many cluster munitions and restricted and regulated the remaining munitions. The U.S. noted that there would be a beneficial humanitarian result on the ground. If the nations suggesting these changes had signed on to the ban there would have been any even more dramatic humanitarian impact on the ground!
The U.S. proposals claimed that cluster munitions are a military necessity. This seems to be the case only for the nations that did not sign the ban. The over 50 nations that objected to the U.S. proposals including the UK are able to function without them. Opponents of their use claim that the weapons are not only indiscriminate but often do not explode only to explode later when disturbed. For more see this article.