Britain, U.S. make case for strike against Syria

President Barack Obama told Americans a military strike against Syria is in their interest following a gas attack last week and Britain said armed action would be legal, but intervention looked set to be delayed until U.N. investigators report back.

Senior Obama administration officials are expected to brief congressional leaders later on Thursday, with lawmakers complaining they have not been properly consulted about plans to respond to what Washington says was the gassing of civilians.

While U.N. chemical weapons inspectors spent a third day combing the rebel-held suburb where the attack took place, elsewhere in Damascus traffic moved normally, with some extra army presence but little indication of any high alert.

A parliamentary debate in London revealed deep misgivings stemming from the 2003 invasion of Iraq. After pressure from lawmakers, the British government - a key player in any proposed air assault on Syria - has promised parliament a decisive vote once the U.N. weapons inspectors report their findings.

The United Nations said its team of inspectors investigating the attacks, which killed hundreds of people, will leave Syria on Saturday and then report to Secretary-General Ban Ki-moon.

France and Germany urged the world body to pass its report on to the decision-making Security Council as soon as possible "so that it can fulfill its responsibility with regards to this monstrous crime".

The United States, Britain and France say they can act with or without a U.N. Security Council resolution, which is likely to be vetoed by Russia, a close ally of Syrian President Bashar al-Assad. However, some countries are raising qualms: Italy said it would not join any military operation without Security Council authorization.

Western diplomats say they are seeking a vote in the 15-member Council to isolate Moscow and demonstrate that other countries are behind air strikes.

"It would be unthinkable to proceed if there was overwhelming opposition in the (U.N.) Security Council," British Prime Minister David Cameron told parliament.