Obama meets Putin ally with Ukraine still in mind

On Tuesday, Obama planned additional meetings on the security summit sidelines: a sit-down with Prince Mohamed bin Zayed, crown prince of Abu Dhabi, the richest emirate in the United Arab Emirates federation, and a joint meeting with Japanese Prime Minister Shinzo Abe and South Korean President Park Geun-hye.

Both those meetings are likely to focus less on Ukraine and more on regional tensions in the Middle East and in Northern Asia.

The visit with the Abu Dhabi crown prince will also serve as precursor to Obama's on Friday visit to Saudi Arabia, where he will meet with King Abdullah to address Arab anxieties over the Syrian civil war and U.S. nuclear talks with Iran, a Saudi Arabia rival in the region.

The meeting with Park and Abe brings together two U.S. Asian allies who have been quarreling over recent Abe gestures that have rekindled memories of Japan's aggression in World War II. It will be the first meeting between the two Asian leaders since they took office more than a year ago.

Despite Monday's Russian bluster and the Ukrainian troop withdrawal, U.S. and other Western officials took note of hopeful signs, including Lavrov's own meeting with his Ukrainian counterpart, the highest-level encounter between the two nations since Russia moved forces into Crimea nearly a month ago.