US President Barack Obama has said he has not yet decided on a plan for retaliatory action against Syria.
But he said he had concluded Syrian government forces were behind a recent chemical weapons attack near Damascus.
Speaking on US television, Mr Obama said the use of chemical weapons affected US national interests and that sending a “shot across the bows” could have a positive impact on Syria’s war.
His comments follow a day of behind-the-scenes wrangling at the UN.
The UK had been pushing for permanent members of the UN Security Council to adopt a resolution which would have authorised measures to protect civilians in Syria.
Damascus seems quieter than on trips I made here earlier this year, though there’s still plenty of traffic in the centre. Its people are awaiting decisions that are being taken elsewhere.
Army roadblocks stop traffic every few miles down the highway in from the Lebanese border, as they have since the war started.
News agencies, quoting residents and some opponents of the Assad regime, have reported that some heavy weaponry has been moved out of bases and staff have partially vacated some headquarters.
It is logical for the Syrian army to have some sort of plan to protect itself from any attack, especially since the progress toward launching a military strike has been discussed so openly by Western powers.
The countries surrounding Syria are bracing themselves for a new crisis. In Beirut, the man who helped me with my bags said the West would do whatever it wanted.
“But please, don’t bomb anywhere near Lebanon. We fear another big war.”
But Syrian ally Russia refused to agree to the resolution and the meeting produced no end to the diplomatic stalemate which has long characterised the UN position on Syria.
The US State Department criticised “Russian intransigence” and said it could not allow diplomatic paralysis to serve as a shield for the Syrian leadership.
Critics have questioned what purpose a limited strike on Syria could serve, but Mr Obama told the Public Broadcasting Service (PBS) it would send the government of Bashar al-Assad “a pretty strong signal that it better not [use chemical weapons] again”.
The US has yet to produce the intelligence it says shows Mr Assad’s government is guilty of using chemical weapons, and UN weapons inspectors are still investigating inside Syria.
UN Secretary General Ban Ki-moon has said they need four more days to complete their investigations and has appealed for the team to be “given time to do its job”.
Syria denies using chemical weapons and blames opposition fighters for the attack on 21 August, which reportedly killed hundreds of people near Damascus.
In a sign of growing fears about an impending attack among Syrians, the Associated Press quoted Lebanese officials as saying at least 6,000 Syrians crossed into Lebanon in a 24-hour period through the main Masnaa crossing – compared to a normal daily tally of between 500 and 1,000 refugees.
“Isn’t it enough, all the violence and fighting that we already have in the country, now America wants to bomb us, too?” one 45-year-old woman, entering Lebanon with her five children, told AP.
In Damascus senior military commanders are reportedly staying away from buildings thought likely to be targeted. You “could hear a pin drop” at one of them, a local resident said.
‘Consequences’
President Obama told PBS that the US had “not yet made a decision, but the international norm against the use of chemical weapons needs to be kept in place, and hardly anyone disputes that chemical weapons were used in a large scale in Syria against civilian populations”.
“We’ve looked at all the evidence, and we don’t believe the opposition possessed chemical weapons of that sort,” he said.
He added he had concluded that the Syrian government carried out the chemical weapons attack.
“There need to be international consequences, so we are consulting with our allies,” he said.
There was “a prospect that chemical weapons could be directed at us – and we want to make sure that doesn’t happen”.
But Mr Obama said he had come to no final decision on what course to take.
The BBC’s David Willis in Washington says this is the most unequivocal sign that Mr Obama has given that he believes the Syrian government is guilty of deploying chemical weapons.
Despite that, our correspondent says, Mr Obama looked cautious and spoke in a measured way, and he was clearly concerned about getting Congress on board as well as the American public.
Opinion polls until now have shown very little interest among the US public in getting involved in the Syrian conflict.
In an open letter to the president, US House of Representatives Speaker John Boehner demanded he explain “the intended effect of military strikes”, and how he would prevent the intervention escalating, if he wanted to win public and congressional backing for action.
More than 110 members of Congress have signed a letter formally requesting that Mr Obama seek congressional approval for any action in Syria.
US officials are expected to give senior members of Congress a classified briefing on the evidence that the Syrian government carried out the alleged chemical attack on Thursday.
Models for possible intervention
Iraq 1991: US-led global military coalition, anchored in international law; explicit mandate from UN Security Council to evict Iraqi forces from Kuwait
Balkans 1990s: US arms supplied to anti-Serb resistance in Croatia and Bosnia in defiance of UN-mandated embargo; later US-led air campaign against Serb paramilitaries. In 1999, US jets provided bulk of 38,000 Nato sorties against Serbia to prevent massacres in Kosovo – legally controversial with UN Security Council resolutions linked to “enforcement measures”
Somalia 1992-93: UN Security Council authorised creation of international force with aim of facilitating humanitarian supplies as Somali state failed. Gradual US military involvement without clear objective culminated in Black Hawk Down disaster in 1993. US troops pulled out
Libya 2011: France and UK sought UN Security Council authorisation for humanitarian operation in Benghazi in 2011. Russia and China abstained but did not veto resolution. Air offensive continued until fall of Gaddafi
The US has said it will not take action alone – but one of its primary allies, the UK, has agreed to wait until UN inspectors report back before taking a final parliamentary vote on potential action.
Russia rejected a UK push to try to agree a resolution on Syria among permanent UN Security Council members on Wednesday, with Foreign Minister Sergei Lavrov saying the UN could not consider any draft resolution or proposed action in Syria before the UN weapons inspectors reported back.
The use of force without a sanction of the UN Security Council would be a “crude violation” of international law and “lead to the long-term destabilisation of the situation in the country and the region”, Mr Lavrov has said.
UN ‘moment’
The UK, US and France are continuing their discussions following the meeting of the five permanent members.
The UK will want to be seen to be exhausting every diplomatic avenue, says the BBC’s Nick Bryant at the UN headquarters in New York.
For the UK, there needs to be a UN “moment” – despite the fact that UN action will likely again be blocked by Russia or China.
But even without UN backing the US and its allies have been clear that they see the military option is still open to them, our correspondent says.
“This is the first use of chemical warfare in the 21st Century,” said UK Foreign Secretary William Hague. “It has to be unacceptable… or we will confront even bigger war crimes in the future.”
More than 100,000 people are estimated to have died since the conflict erupted in Syria in March 2011, and the conflict has produced at least 1.7 million refugees. (BBC)
