Ten G20 nations back United States over Syria

But the tough language aligned half of the G20 members with the US president, who worked the sidelines of the summit in St Petersburg to build international support for a limited US military response.

The 10 countries were the UK, Australia, Canada, France, Italy, Japan, South Korea, Saudi Arabia, Spain and Turkey.

Earlier Mr Obama said there was a growing recognition among foreign leaders that “the world cannot stand idly by” in the face of chemical weapons use in Syria.

Mr Obama is seeking congressional authority to launch a strike and will address the US nation on Tuesday as he seeks public support.

He said he understood the American public’s scepticism about action against Syria, but added that he was confident he could persuade them that the use of chemical weapons requires a military response.

The president said he needed to convince the nation that his plans would be “limited and proportional” and designed to uphold international norms.

He said: “I trust my constituents want me to offer my best judgment. That’s why they elected me. That’s why they re-elected me.”

With Congress reluctant to back a resolution authorising military strikes, Mr Obama refused to say whether he would act if he failed to win that approval.

“It would be a mistake for me to jump the gun and speculate because right now I’m working to get as much support as possible out of Congress,” he said.

Mr Obama told reporters at the end of the G20 summit that he and other leaders had had a “full airing of views on the issue”. and that they were unanimous in believing that chemical weapons were used in Syria and that international norms against that use must be maintained.

He said any division comes over how to proceed through the United Nations.

Mr Obama also held a surprise meeting with Russian president Vladimir Putin, a chief opponent of US military action. Mr Putin, a staunch ally of Assad, said this discussion focused on Syria during the 20 to 30 minutes and that, while they disagreed, the meeting was “substantial and constructive”.

Mr Obama called the discussion “candid and constructive”, even if they still disagreed on how to respond to the chemical weapons. He said they agreed that the underlying conflict could only be resolved through a political transition. Mr Obama said he thought it was important that he and Mr Putin work together to urge all sides in the conflict to try to resolve it.

However Russia warned the US and its allies against striking any chemical weapon storage facilities in Syria. The Russian foreign ministry said such targeting could release toxic chemicals and give militants or terrorist access to chemical weapons.

“This is a step toward proliferation of chemical weapons not only across the Syrian territory but beyond its borders,” the Russian statement said.

The talks were held as the Syrian government dispatched reinforcements including tanks and armoured personnel carriers to a predominantly Christian village north of Damascus where rebels have clashed with regime troops.

Opposition fighters led by an al Qaida-linked rebel faction attacked the mountainside sanctuary of Maaloula on Wednesday, and briefly entered the village a day later before pulling out in the evening.

The assault has spotlighted fears among Syria’s religious minorities about the prominent role of Islamic extremists in the rebel ranks fighting to overthrow Assad.

The government forces sent to Maaloula have taken up positions outside the village, which is still under the control of local pro-regime militias, said Rami Abdul-Rahman, the director of the Britain-based Syrian Observatory for Human Rights.

The assault is being spearheaded by Jabhat al-Nusra, one of the most effective rebel factions and a group the United States has deemed a terrorist organisation. The group includes Syrians as well as foreign fighters from across the Muslim world.

The Syrian government has tried to emphasise the role of foreigners fighting on the rebel side as part of its narrative that the Assad regime is battling a foreign-backed conspiracy.

In that vein, Syrian state television said Friday the government is offering 500,000 Syrian pounds (£2,800) for turning in a foreign fighter, and 200,000 Syrian pounds (£1,150) for information about their whereabouts or assistance in their capture.

Russia’s Interfax news agency said Moscow had three naval ships moving toward Syria in the eastern Mediterranean and another en route from the Black Sea. The agency said two amphibious landing crafts and a reconnaissance ship have already passed through the Dardanelles, while another landing vessel left the Black Sea port of Sevastopol this morning for the Eastern Mediterranean with “special cargo”.

Kremlin chief of staff Sergei Ivanov said Russia is boosting its naval presence in the Mediterranean “primarily” to organise a possible evacuation of Russians from Syria.

Reports of increased Russian naval presence near Syria have stoked fears about a larger international conflict if the United States carries out air strikes.

In Damascus, the Syrian state news agency SANA said the speaker of parliament, Mohammad Jihad Laham, urged the US Congress to engage in a “civilised” dialogue with Damascus rather than resorting to a dialogue of “fire and blood”.

Meanwhile, the United Nations envoy for Syria met foreign ministers at the G20 to push for a political solution for Syria.

Lakhdar Brahimi, the UN and Arab League envoy for the Syrian crisis, had a working breakfast with ministers from Russia, Canada, France, Germany and Turkey among others.

Speaking to reporters, he emphasised the need to wait until UN inspectors complete their analysis of the chemical attack. He said the work “has to be completed according to scientific standards”, but did not say when this might be done.

Mr Brahimi warned against using force without the UN Security Council’s approval and called for further efforts to stage a Syria peace conference.

Mr Obama refused to say what he would do if Congress does not approve Syria strikes.

But said his discussions with Mr Putin were “candid and constructive”, and added that leaders from Europe, Asia and the Middle East agree that international norms against the use of chemical weapons must be upheld.

Mr Putin said Russia will continue helping Syria even if it comes under attack.

He answered with a firm “we will” when asked if Moscow will keep providing assistance to Syria if it’s attacked.

He added that Russia has been supplying weapons to Syria and maintaining economic co-operation, and said he intends to increase humanitarian assistance to the Syrian people after more than two years of hostilities.

Elsewhere, Iraqi officials and militant groups said Iranian-backed Shiite militias were threatening to retaliate against US interests in Iraq if Washington goes ahead with strikes against Syria, a close ally of Tehran.

Cleric Wathiq al-Batat said his Iranian-backed Mukhtar Army is preparing for a forceful reaction against the interests of the US and other countries that take part in any Syria strike.

The United States Embassy in Baghdad had no immediate response to the threats.