Amid tensions, Obama, Putin put on a happy face

ST. PETERSBURG, Russia (AP) - President Barack Obama and his Russian counterpart Vladimir Putin shook hands, smiled and made small talk about the scenery on Thursday - a public exchange of pleasantries belying a tense relationship that only seems to be getting worse.

"We've kind of hit a wall," Obama said of the United States' ties with Russia the day before he arrived in St. Petersburg for a global summit.

With tensions mounting over issues including Syria, National Security Agency leaker Edward Snowden, and human rights, Obama and Putin did not plan to hold a formal bilateral meeting on the sidelines of the G-20 gathering. A formal greeting outside St. Petersburg's Constantine Palace was their only planned one-on-one public appearance.

Parsing the body language between Obama and Putin has become something of a geopolitical parlor game every time the two leaders meet. But there wasn't much to work with this time: Their exchange lasted 15 seconds.

Obama's black armored limousine pulled up to the palace where Putin was waiting to greet each of the leaders. The U.S. president was the only leader who used his own official vehicle for the arrival, opting not to use the summit-issued Mercedes the other 19 leaders used.

The two leaders, both smiling, greeted each other with a handshake. Obama gestured toward the palace and the bright blue sky, declaring the location "beautiful."

Obama and Putin may talk again on the sidelines of the summit, including Thursday night at a leaders' dinner where Syria was expected to be discussed. But any discussion would be private.

Differences over Syria have heightened tensions between Obama and Putin since the civil war there started more than two years ago. While the U.S. president has called for Syrian President Bashar Assad's ouster, the Russian leader has helped prop up the Syrian government, both economically and militarily.