Diplomats said the U.N. Security Council will decide Tuesday whether to impose sanctions on a South Sudan army chief and a former army general who is now a rebel commander for continuing to fuel conflict in the world's newest nation.

The United States has proposed imposing a travel ban and asset freeze on Gen. Paul Malong and ex-general Johnson Olony who has joined rebel leader Riek Machar, the diplomats said Monday, speaking on condition of anonymity because their names have not been made public.

The council has until 3 p.m. EDT (1900 GMT) Tuesday to object to adding their names to the U.N. sanctions list.

Fighting broke out in December 2013 after President Salva Kiir accused ex-vice president Machar of trying to oust him, and has continued despite a recent agreement.