Mexico's President Enrique Pena Nieto attends the opening ceremony 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 / POOL/AFP/Getty Images

Spain's Prime Minister Mariano Rajoy attends the opening ceremony 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 / POOL/AFP/Getty Images

Saudi Arabia's Deputy Crown Prince and Minister of Defense Muhammad bin Salman attends the opening ceremony 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 / POOL / Nicolas ASFOURINICOLAS ASFOURI/AFP/Getty Images

South Korea's President Park Geun-Hye attends the opening ceremony 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 / POOL / Nicolas ASFOURINICOLAS ASFOURI/AFP/Getty Images

Thailand's Prime Minister Prayut Chan-O-Cha attends the opening ceremony 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 / POOL / Nicolas ASFOURINICOLAS ASFOURI/AFP/Getty Images

China's President Xi Jinping (centre L), Russia's President Vladimir Putin (C), Kazakhstan's President Nursultan Nazarbayev (centre R), and President of the European Commission Jean-Claude Juncker (R, behind window) walk with other G20 leaders and their spouses for a group picture prior to a dinner banquet at the G20 Summit 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 / Johannes EISELEJOHANNES EISELE/AFP/Getty Images

US President Barack Obamas (L) speaks to French President Francois Hollande (R) on 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 / JOHANNES EISELEJOHANNES EISELE/AFP/Getty Images

Japan's Prime Minister Shinzo Abe listens to a speech by Chinese President Xi Jinping (not pictured) during the opening ceremony 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 / POOL / Nicolas ASFOURINICOLAS ASFOURI/AFP/Getty Images