South Korea's President Park Geun-Hye arrives for the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / POOL / Rolex DELA PENAROLEX DELA PENA/AFP/Getty Images

South Africa's President Jacob Zuma arrives for the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / POOL / Rolex DELA PENAROLEX DELA PENA/AFP/Getty Images

Argentina's President Mauricio Macri arrives for the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / POOL / Rolex DELA PENAROLEX DELA PENA/AFP/Getty Images

Argentina's President Mauricio Macri arrives for the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / POOL / Rolex DELA PENAROLEX DELA PENA/AFP/Getty Images

A view of the King Abdullah Financial District in the Saudi capital Riyadh at sun set October 9, 2013. REUTERS/Faisal Al Nasser

Egypt's President Abdel Fattah al-Sisi arrives for the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / POOL / Rolex DELA PENAROLEX DELA PENA/AFP/Getty Images

Saudi Arabia Deputy Crown Prince Mohammed bin Salman (L) arrives for the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / POOL / Rolex DELA PENAROLEX DELA PENA/AFP/Getty Images

US President Barack Obama (3rd L front) and China's President Xi Jinping (3rd R front) gesture as they gather with German Chancellor Angela Merkel (C front), Russia's President Vladimir Putin (R front) and Turkey's President Recep Tayyip Erdogan (2nd R front) during a group photo before the opening of the G20 Summit at the International Expo Center in Hangzhou on September 4, 2016. G20 leaders confront a sluggish global economy and the winds of populism as they open annual talks, but the long war in Syria and the South China Sea territorial dispute hang over the summit. / AFP PHOTO / GREG BAKERGREG BAKER/AFP/Getty Images