The UN Security Council has failed to back an appeal from UN aid officials for a month- long humanitarian ceasefire in Syria, where four days of government raids have killed scores of civilians.
Russia dismissed the proposal as unrealistic but Kuwait and Sweden, which requested the meeting, said they were considering other ways to address the worsening humanitarian crisis in the war-wracked country.
Asked about the one-month pause, Russian Ambassador Vassily Nebenzia said, "That is not realistic."
"We would like to see a ceasefire, the end of the war, but the terrorists, I am not sure, are in agreement," he told reporters.
The UN humanitarian coordinator for Syria, Panos Moumtzis, on Tuesday called for the month-long ceasefire to reach civilians in need as fighting in Eastern Ghouta and Idlib escalated.
But there was no agreement on a council statement, which requires consensus among the 15 members, diplomats said.
"Eastern Ghouta is experiencing a Middle Ages-style siege. That is totally unacceptable," Delattre told reporters.
"In Syria, we are now back to the darkest period of this conflict, with the highest death toll among civilians over the last year," he deplored.
The United States demanded an end to the air strikes, with the State Department saying in Washington: "These attacks must end now."
UN aid officials accuse the Syrian government of blocking all aid convoys to besieged areas since January.
More than 13.1 million Syrians are in need of humanitarian aid, including 6.1 million who have been displaced within the country during the nearly seven-year war.