United Nations diplomats from the United States, Russia, France, China and Britain launched talks on Wednesday on a draft resolution from Britain calling for the world body to "do what is necessary" to protect civilians and prevent further attacks.
There was no comment on the proposal after diplomats left the meeting.
Britain is pushing for a U.N. Security Council vote on the measure, a prelude to possible military action against Syria.
Military forces around Syria
"We believe that it is time the United Nations Security Council shouldered its responsibilities on Syria, which for the last two and half years it has failed to do," said Foreign Secretary William Hague, who accused the world body of foot-dragging.
VOA's United Nations correspondent said the P-5 envoys had no comments after Wednesday's session and the diplomats for Russia and China left before the other envoys. Both nations have previously resisted U.N. efforts to penalize the Syrian regime for alleged abuses during its civil war.
The proposed resolution is part of an international diplomatic effort by the U.S. and Western powers before possible military action against President Bashar al-Assad.
A U.N. team conducting an on-site investigation of the alleged gas attack in suburban Damascus wrapped up its work for Wednesday, but U.N. Secretary-General Ban Ki-moon said the team will need four days to complete its probe.
Ban is in The Hague, where he discussed efforts to convene a political conference on Syria with Russian Deputy Foreign Minister Gennadiy Gatilov. He also urged the U.N. Security Council to "find unity" on the situation in Syria.
Syria denies accusations
The Syrian government has denied having any role in last week's alleged gas attack, which left hundreds dead.
Deputy Foreign Minister Faisal Maqdad blamed Western-backed 'terrorists' for the incidents.
"Armed terrorist groups used Sarin gas in all these sites, and we repeat that the terrorist groups are the ones who used them with American, British and French encouragement. This encouragement should stop,'' he said.
Syria's U.N. envoy, Bashar Ja'afari, called for the U.N. team to investigate what he said are three new allegations of poison gas use against troops. He also said if attacked, Syria had a "right to self defense."
In Brussels, NATO Secretary-General Anders Fogh Rasmussen said information from a variety of sources indicated the Syrian regime was responsible for chemical weapons attacks. He said any use of chemical weapons could "not go unanswered."
Story contnues below photogallery
Some information for this report was provided by AFP and Reuters.