Western envoys have told the Syrian opposition to expect a military response soon against President Bashar al-Assad's forces as punishment for a chemical weapons attack last week, according to sources who attended a meeting with the rebel Syrian National Coalition in Istanbul.
UK Prime minister David Cameron will hold war talks at Downing Street today (28 August) as military commanders draw up plans for missile strikes against Syria.
Cameron will chair a meeting of the National Security Council (NSC) after insisting the West must not "stand idly by" in the wake of Syria's suspected chemical attack.
Last night, he held talks with US President Barack Obama by telephone as military strikes against the Assad regime looked increasingly likely.
Foreign Secretary William Hague ramped up the pressure to act on "barbarous" Syria by setting out the case for action in a national newspaper comment piece.
Meanwhile, French President François Hollande said on Tuesday (27 August) that France stood ready to punish those behind a chemical attack on civilians in Damascus last week and would increase its military support of the Syrian opposition.
Hollande said it seemed certain that forces loyal to Assad were behind the chemical attack - believed to have killed hundreds of civilians - and said it was the outside world's responsibility to respond.
He said he recognised a 2005 United Nations doctrine on the responsibility to protect civilians, something a Western-led coalition might use to legitimise any retaliatory strike if unable to obtain a broad Security Council resolution.
"France is ready to punish those who took the decision to gas the innocent," Hollande told an annual meeting in Paris of dozens of French ambassadors posted around the world.
"I recognise the right to protect civilian populations that the UN General Assembly voted in 2005," he added.
Amid a quickening drumbeat of preparations, Australia, a close US ally and incoming chair of the United Nations Security Council, on Wednesday endorsed possible action against Syria even if the security council fails to agree.
US Defence Secretary Chuck Hagel said on Tuesday that American forces in the region were "ready to go" if President Barack Obama gave the order.