GENEVA — Despite last-minute attempts to broker a compromise, American-led efforts to conclude an international treaty restricting use of cluster munitions collapsed on Friday in the face of opposition from countries that said it did not address their humanitarian concerns and would undermine existing international law.

Diplomats from 114 countries spent two weeks in Geneva trying to conclude a treaty that would have banned older, less sophisticated cluster munitions — bombs and rockets that scatter a large number of smaller bomblets over a wide area. Some bomblets fail to explode upon hitting the ground and can remain a deadly hazard long after the fighting is over.

The draft treaty was vigorously promoted by the United States and had the backing of other major users and producers, including China, India, Israel and Russia. It reflected the increasing stigmatization of a weapon recognized as causing unacceptable harm to civilians and seen as having lasting effects on development for decades after conflicts have ended.

The effort was rejected by a group of 50 countries from Africa, Asia, Europe and Latin America, including many nations that had signed on to the 2008 Oslo Convention. The Oslo agreement imposed a comprehensive ban on the use, production, stockpiling and sale of cluster munitions.