Obama and Putin Meet Briefly in Beijing

U.S. President Barack Obama and his Russian counterpart Vladimir Putin met briefly Monday in Beijing on the sidelines of an Asia-Pacific summit, a senior U.S. official said.

The two leaders, who have been engaged for months in a standoff over the crisis in Ukraine, "only had a brief encounter where they didn't have time to cover issues," the official said on condition of anonymity.

The encounter between the two at an APEC summit in Beijing comes amid reports of armored columns heading toward the pro-Moscow rebel stronghold of Donetsk in eastern Ukraine on Monday as fears grow of a return to all-out fighting in the war-torn region.

Putin and Obama last met informally on the sidelines at a lunch for world leaders at the 70th anniversary commemorations of the D-Day landings in Normandy, France, in June.

U.S.-Russia relations are at their lowest since the Cold War, with Russia under US-backed Western sanctions over its seizure of the Crimea this year and its role in the separatist war in eastern Ukraine.

In mid-October, Putin accused Obama of having a hostile attitude towards Russia, while Obama decried "Russian aggression in Europe" in a recent speech to the United Nations General Assembly.