The Russian defense minister proposed on Friday that Russia and the U.S.-led coalition launch joint action against al-Qaida’s branch in Syria, known as the Nusra Front.

A spokesman for the U.S. State Department said no agreement on such action has been made with Russia.

Defense Minister Sergei Shoigu said that Moscow had proposed to Washington that the coalition call on all factions eager to abide by a cease-fire in Syria to leave the areas where the al-Qaida branch is active by May 25. Then Russia and the U.S.-led coalition could conduct joint strikes against the Nusra Front and any other groups refusing to honor the truce, Shoigu suggested.

State Department spokesman John Kirby said “there is no agreement to conduct joint airstrikes with the Russians in Syria” but added Washington and Moscow are discussing “proposals for a sustainable mechanism to better monitor and enforce the cessation of hostilities.”