US President Barack Obama (R) and Turkish President Recep Tayyip Erdogan (2nd-L) hold a meeting on the sidelines of 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 / SAUL LOEBSAUL LOEB/AFP/Getty Images

US President Barack Obama (R) and Turkish President Recep Tayyip Erdogan (3rd-L) hold a meeting on the sidelines of 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 / SAUL LOEBSAUL LOEB/AFP/Getty Images

Turkish President Recep Tayyip Erdogan speaks during a meeting with US President Barack Obama (not pictured) on the sidelines of 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 / SAUL LOEBSAUL LOEB/AFP/Getty Images

US President Barack Obama holds a meeting with Turkish President Recep Tayyip Erdogan (not pictured) on the sidelines of 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 / SAUL LOEBSAUL LOEB/AFP/Getty Images

Britain's Prime Minister Theresa May (R) and Saudi Arabia's Deputy Crown Prince, Second Deputy Prime Minister and Minister of Defense Muhammad bin Salman Al Saud (L) hold a bilateral meeting before the start of the G20 Summit in Hangzhou on September 4, 2016. G20 leaders meet, charged with reviving the sluggish world economy, but a growing anti-globalisation mood and alarm over China's territorial ambitions loom over the summit in the scenic city of Hangzhou. / AFP PHOTO / POOL / NARENDRA SHRESTHANARENDRA SHRESTHA/AFP/Getty Images

Britain's Prime Minister Theresa May (R) and Saudi Arabia's Deputy Crown Prince, Second Deputy Prime Minister and Minister of Defense Muhammad bin Salman Al Saud (L) hold a bilateral meeting before the start of the G20 Summit in Hangzhou on September 4, 2016. G20 leaders meet, charged with reviving the sluggish world economy, but a growing anti-globalisation mood and alarm over China's territorial ambitions loom over the summit in the scenic city of Hangzhou. / AFP PHOTO / POOL / NARENDRA SHRESTHANARENDRA SHRESTHA/AFP/Getty Images

Britain's Prime Minister Theresa May (center-R) and Saudi Arabia's Deputy Crown Prince, Second Deputy Prime Minister and Minister of Defense Muhammad bin Salman Al Saud (center-L) hold a bilateral meeting before the start of the G20 Summit in Hangzhou on September 4, 2016. G20 leaders meet, charged with reviving the sluggish world economy, but a growing anti-globalisation mood and alarm over China's territorial ambitions loom over the summit in the scenic city of Hangzhou. / AFP PHOTO / POOL / NARENDRA SHRESTHANARENDRA SHRESTHA/AFP/Getty Images

An Indian Nun from the Catholic Order of the Missionaries of Charity walks after mass at a church in Mumbai on September 4, 2016, ahead of the canonisation of Mother Teresa in Rome. Indian Christians are eagerly looking forward to the canonisation of Mother Teresa and churches across the country would be holding special masses in her honour. As the Vatican prepares to declare Mother Teresa a saint on September 4, in the Indian city where she rose to fame, claims of medical negligence and financial mismanagement at her care homes threaten to cloud her legacy. / AFP PHOTO / INDRANIL MUKHERJEEINDRANIL MUKHERJEE/AFP/Getty Images