Updated

Russia's Foreign Ministry says that Washington's openness to a no-fly zone over Syria has raised doubts about the sincerity of U.S. support for a peace conference on Syria.

White House spokesman Jay Carney said Wednesday that every option, including the possibility of a no-fly zone, remains on the table.

The Russian Foreign Ministry responded Thursday by urging Washington to stick to its pledge to help broker a Syria peace conference together with Moscow. It cautioned the U.S. against a "bellicose agenda on Syria."

The ministry added that the talk about the no-fly zone along with the EU's decision to lift arms embargo for Syrian rebels "raised doubts about the sincerity of some of our international and regional partners regarding international efforts to achieve a political settlement."