Russia, now discussing a military cooperation agreement with the United States in Syria, is still far from American positions, US Defense Secretary Ashton Carter said Monday.

Talks led by Secretary of State John Kerry are aimed at seeing if "it's possible... for the Russians to begin to do the right thing in Syria," Carter said.

In other words, Russia's policies that have prolonged the war should end, he said.

"We had hoped that they would promote a political solution and transition to put an end to the civil war which is the beginning of all this violence in Syria," Carter said referring to the regime of President Bashar al-Assad.

But "they're a long way from doing that," Carter stressed. "But that's what Secretary Kerry's trying to promote. And getting the Russians to do the right thing."

Russia and the United States back opposing sides in Syria's five-year war, which has left 280,000 people dead and forced half the population to flee their homes.

Multiple rounds of international negotiations to end the war, which erupted in 2011 after Assad's regime unleashed a brutal crackdown against a pro-democracy revolt, have so far failed.

Kerry held marathon talks with Russian President Vladimir Putin and Foreign Minister Sergei Lavrov in Moscow last week, striking an agreement on "concrete steps" to salvage a failing truce and tackle jihadist groups in Syria.

Details of the deal have not been made public but some US officials have voiced concerns about the effort.

US intelligence chief James Clapper was quoted in a Washington Post story on Thursday as saying: "I've expressed my reservations about, for example, sharing intelligence with (the Russians)... which they desperately want, I think, to exploit, to learn what they can about our sources and methods and tactics and techniques and procedures," he said.

Chairman of the Joint Chiefs of Staff General Joe Dunford said Monday, "we're not entering into a transaction that's founded on trust.

"There will be specific procedures and processes in any transaction we might have with the Russians that would -- that would account for protecting our operational security."

Damascus-backer Russia and the United States, which supports moderate rebels seeking to unseat Assad, co-chair a 22-member group working to end the war in Syria. 

A ceasefire they brokered in February -- which did not include the Islamic State group or Syrian Al-Qaeda branch Al-Nusra -- has since all but collapsed amid continued heavy fighting.

US President Barack Obama has insisted on keeping dialogue with Moscow open on Syria, Kerry has said.

Source: AFP