Oxford: On Wednesday US Defense Secretary Ash Carter accused Russia of sowing seeds of global instability and questioned whether Moscow genuinely wants a viable cease-fire in Syria.
In a hard-hitting speech at Oxford University, Carter emphasized deep skepticism about Russian intentions in Syria, even as US Secretary of State John Kerry prepared to fly to Geneva for more talks with Russian Foreign Minister Sergey Lavrov.
Their discussions last weekend, on the sidelines of an economic summit in China, failed to produce a nationwide cease-fire in Syria or a US-Russian military cooperation agreement.
Russia is a firm supporter of Syrian President Bashar Assad, and their joint military operation has sometimes targeted the anti-Islamic State rebels backed by the Obama administration.
The Russian Foreign Ministry said Kerry and Lavrov would hold their next round of talks Thursday and Friday.
"Unfortunately so far, Russia, with its support for the Assad regime, has made the situation in Syria more dangerous, more prolonged and more violent. That has contributed to what President Obama this weekend called the 'gaps of trust' that exist between our two countries," Carter said.
In last weekend's talks, top diplomats from the US and Russia, as well as President Barack Obama and Russian President Vladimir Putin, struggled to keep alive negotiations to end the bloodshed between US-backed rebels and Syria's government.
Obama expressed skepticism that an unlikely alliance between rivals would yield the breakthrough needed to end the 5-year-old civil war.
Carter urged the Russians to work with the US toward a political transition in Syria, though he sounded less than optimistic.
"Today's news out of Syria is not encouraging," he said. "The choice is Russia's to make and the consequences will be its responsibility."
Intense fighting between Syrian government troops and insurgents in Syria's central Hama province displaced some 100,000 people over eight days between late August and early September, the UN's humanitarian agency reported
"Despite the progress that we made together in the aftermath of the Cold War, Russia's actions in recent years with its violations of Ukrainian and Georgian territorial integrity, its unprofessional behavior in the air, in space, and in cyberspace, as well as its nuclear saber rattling - all have demonstrated that Russia has clear ambition to erode the principled international order," Carter said.
Carter accused Russia of being driven by "misguided ambition and misplaced fear."