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. 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.

Putin also has criticized Obama’s push toward potential military action against Syria to punish it for an Aug. 21 chemical weapons attack.

Upon coming into office, Obama made a high-profile effort to “reset” relations with Russia. He made progress with former President Dmitry Medvedev, including on missile defense and opening more transit lines from Afghanistan. But the relationship began to fray when Putin reassumed the presidency.

Since then, the two leaders have held several meetings on the world stage, where their stiff body language has signaled a troubled relationship. During a news conference, Obama described Putin’s notorious slouch that made him look like “the bored kid at the back of the classroom.”

In an interview this week, Putin played down the notion of personal tensions with his U.S. counterpart.

“President Obama hasn’t been elected by the American people in order to be pleasant to Russia,” Putin said. “And your humble servant hasn’t been elected by the people of Russia to be pleasant to someone, either.”

The relationship hit perhaps its lowest point this summer when Russia granted temporary asylum to Snowden, the former government contractor.

The Kremlin’s decision came despite pleas from the Obama administration to return Snowden to the U.S. to face espionage charges after he absconded with a trove of documents detailing secret U.S. surveillance programs and leaked them to the media.

In retaliation, Obama called off plans to meet one-on-one with Putin in Moscow ahead of this week’s summit.