SAINT PETERSBURG – SEPTEMBER 05: In this handout image provided by Host Photo Agency, Russian President Vladimir Putin (L) and U.S. President Barack Obama shake hands during an official welcome during the G20 Summit on September 5, 2013 in St. Petersburg, Russia. The G20 summit is expected to be dominated by the issue of military action in Syria while issues surrounding the global economy, including tax avoidance by multinationals, will also be discussed during the two-day summit. (Photo by Alexey Kudenko/Host Photo Agency via Getty Images)
