LOS CABOS: US President Barack Obama said China and Russia are “not aligned” with the US and other nations on Syria but says both countries’ leaders recognise the dangers of a civil war.

Obama's comments at the end of the Group of 20 meeting of the world's largest economies came after Russian President Vladimir Putin said only the Syrian people have the right to decide whether their leader, Bashar al Assad, steps down.

He added that he told Putin and Chinese President Hu Jintao on the sidelines of the summit that Assad could no longer remain in power after the massacres of large numbers of civilians.

“I wouldn’t suggest that at this point the United States and the rest of the international community are aligned with Russia and China... but I do think they recognize the grave dangers of all out civil war,” Obama said.

China and Russia, however, did support an observer mission in Syria and a plan by special envoy Kofi Annan to end the violence.

Obama said Russia and China believe “everyone would be better served” if Syria had a mechanism for ceasing the violence

Russia resisted Western pleas Tuesday to help remove Syria’s President Bashar Assad from power despite escalating hostilities that have battered a UN peace mission.

“We believe that nobody has the right o decide for other nations who should be in power and who should not,” Russian President Vladimir Putin told reporters after a G20 summit at this Mexican beach resort.

“It is not changing the regime that is important, but that after changing the regime, which should be done constitutionally, violence is stopped and peace comes to the country,” he said.

Putin made the comments shortly after British Prime Minister David Cameron said the Russian leader had made clear he does not want Assad to remain in charge.

Putin told a news conference that only some Syrians ''who are represented by the armed position'' want Assad to step down.

''It's my personal belief, and I shared this with them, I don't see a scenario in which Assad stays and violence is reduced,'' Obama countered.

US President Barack Obama and Turkey's Prime Minister Recep Tayyip Erdogan also met at the G20 summit Tuesday to discuss the need for a political transition in Syria.

Erdogan has become a key ally for Obama in the three years since he took office and the two men have met and spoken by telephone frequently to discuss various Middle East crises.

“They discussed the importance of moving toward a political transition in Syria that ends bloodshed and brings about a government that reflects the will of the Syrian people,” a White House statement said.

“They also discussed the situation in Iraq, and agreed on their support for its unity. They reviewed the need to enhance counterterrorism cooperation,” the statement said, adding the leaders also discussed economic cooperation.

Turkey has been the venue for meetings of various Syrian opposition groups opposed to President Bashar al-Assad.

The country has also registered more than 30,000 refugees who have fled over its borders from Syria, officials said.

France’s President Francois Hollande, however, said Russia “is playing its role to permit a transition.” He added: “Those who are massacring their people today cannot play a role in the future of Syria.”

The US military said meanwhile that Russia was preparing to deploy three naval ships to Syria for a mission that Moscow says is purely designed to ferry supplies to its base at the port of Tartus.

“Russian citizens have been threatened there in Syria, and their stated intention is that this is for force protection reasons of their own. That's what we believe to be the case,” Pentagon spokesman Captain John Kirby told reporters.

They were in addition to a Russian cargo ship allegedly carrying attack helicopters to Syria, which was turned back from British waters after its insurance coverage was revoked.