TO GO WITH AFP STORY BY MARIA PANINA (FILES) This file photo taken on September 05, 2013 shows Russias President Vladimir Putin (L) welcoming US President Barack Obama at the start of the G20 summit in Saint Petersburg. The G20 summit starting in China on September 4, 2016 gives Russian President Vladimir Putin one more chance to try to strongarm US leader Barack Obama over Syria and Ukraine as their fraught relationship nears an end. In recent years the two world leaders have barely been able to hide their disdain for each other as ties between Washington and Moscow fell to their lowest level since the Cold War over the crisis in Ukraine. Now with elections for a new US president just over two months away, Russian analysts say an emboldened Putin could see the G20 as an opportunity to press for concessions from Obama, particularly on Syria if he wants to make progress on the war before leaving office. / AFP PHOTO / POOL / Pablo MARTINEZ MONSIVAISPABLO MARTINEZ MONSIVAIS/AFP/Getty Images

TO GO WITH AFP STORY BY MARIA PANINA (FILES) This file photo taken on September 5, 2013 shows Russias President Vladimir Putin (L) welcoming US President Barack Obama at the start of the G20 summit in Saint Petersburg. The G20 summit starting in China on September 4, 2016 gives Russian President Vladimir Putin one more chance to try to strongarm US leader Barack Obama over Syria and Ukraine as their fraught relationship nears an end. In recent years the two world leaders have barely been able to hide their disdain for each other as ties between Washington and Moscow fell to their lowest level since the Cold War over the crisis in Ukraine. Now with elections for a new US president just over two months away, Russian analysts say an emboldened Putin could see the G20 as an opportunity to press for concessions from Obama, particularly on Syria if he wants to make progress on the war before leaving office. / AFP PHOTO / ALEXANDER NEMENOVALEXANDER NEMENOV/AFP/Getty Images

TO GO WITH AFP STORY BY MARIA PANINA (FILES) This file photo taken on September 28, 2015 shows US President Barack Obama (R) and Russia's President Vladimir Putin (L) posing for a photo ahead of a bilateral meeting on the sidelines of the 70th session of the UN General Assembly at the United Nations headquarters in New York. The G20 summit starting in China on September 4, 2016 gives Russian President Vladimir Putin one more chance to try to strongarm US leader Barack Obama over Syria and Ukraine as their fraught relationship nears an end. In recent years the two world leaders have barely been able to hide their disdain for each other as ties between Washington and Moscow fell to their lowest level since the Cold War over the crisis in Ukraine. Now with elections for a new US president just over two months away, Russian analysts say an emboldened Putin could see the G20 as an opportunity to press for concessions from Obama, particularly on Syria if he wants to make progress on the war before leaving office. / AFP PHOTO / MANDEL NGANMANDEL NGAN/AFP/Getty Images

This picture taken on June 3, 2016 shows 13 year-old Viet (L) lying in recovery at a hospital with his brother after losing several fingers to an unexploded bomblet in Xieng Khoang. The legacy of the secret bombing campaign the United States conducted in a sideshow to the Vietnam War and its enduring consequences will feature prominently during a visit September 2016 by Barack Obama, the first ever by a US president to Laos. During the trip he is expected to announce the ramping up of a US programme to clear unexploded devices, echoing similar moves Washington took in Vietnam as relations between the two former foes blossomed. / AFP PHOTO / ALISON MCCAULEY / TO GO WITH AFP STORY LAOS-US-DIPLOMACY-CONFLICT-OBAMA,FOCUS BY CORALINE MOLINIEALISON MCCAULEY/AFP/Getty Images

This picture taken on June 2, 2016 shows Yhong Vueyha being measured for a prosthetic arm by a COPE (Cooperative Orthotic and Prosthetic Enterprise) employee at a mobile clinic in Xieng Khoang. The legacy of the secret bombing campaign the United States conducted in a sideshow to the Vietnam War and its enduring consequences will feature prominently during a visit September 2016 by Barack Obama, the first ever by a US president to Laos. During the trip he is expected to announce the ramping up of a US programme to clear unexploded devices, echoing similar moves Washington took in Vietnam as relations between the two former foes blossomed. / AFP PHOTO / CAROLINE MOLINIE / TO GO WITH AFP STORY LAOS-US-DIPLOMACY-CONFLICT-OBAMA,FOCUS BY CORALINE MOLINIECAROLINE MOLINIE/AFP/Getty Images

This picture taken on May 28, 2016 shows bomblets from a cluster bomb hanging at the Visitor Centre of COPE, a Laos charity working with the Ministry of Health specialising in limbs for amputees, in Vientiane. The legacy of the secret bombing campaign the United States conducted in a sideshow to the Vietnam War and its enduring consequences will feature prominently during a visit September 2016 by Barack Obama, the first ever by a US president to Laos. During the trip he is expected to announce the ramping up of a US programme to clear unexploded devices, echoing similar moves Washington took in Vietnam as relations between the two former foes blossomed. / AFP PHOTO / ALISON MCCAULEY / TO GO WITH AFP STORY LAOS-US-DIPLOMACY-CONFLICT-OBAMA,FOCUS BY CORALINE MOLINIEALISON MCCAULEY/AFP/Getty Images

This picture taken on June 2, 2016 shows workers from COPE (Cooperative Orthotic and Prosthetic Enterprise), holding a prostetic leg at a mobile clinic in Xieng Khoang. The school holidays had only just begun when Viet became one of the latest casualties of the United States' secret bombing campaign in Laos.The 13-year-old was helping his family clear fields in early June when his shovel disturbed one of the millions of cluster bomblets that still litter his homeland.The legacy of that war and its still palpable present day consequences will feature prominently during a visit next week by Barack Obama, the first ever by a US president to Laos. The legacy of the secret bombing campaign the United States conducted in a sideshow to the Vietnam War and its enduring consequences will feature prominently during a visit September 2016 by Barack Obama, the first ever by a US president to Laos. During the trip he is expected to announce the ramping up of a US programme to clear unexploded devices, echoing similar moves Washington took in Vietnam as relations between the two former foes blossomed. / AFP PHOTO / CAROLINE MOLINIE / TO GO WITH AFP STORY LAOS-US-DIPLOMACY-CONFLICT-OBAMA,FOCUS BY CORALINE MOLINIECAROLINE MOLINIE/AFP/Getty Images

WASHINGTON, DC - AUGUST 31: Georgetown University Law Center's O'Neill Institute for National and Global Health Law Senior Scholar Daniel Lucey participates in a panel discussion on the Zika virus at the law center August 31, 2016 in Washington, DC. Centers for Disease Control and Prevention Director Dr. Thomas R. Frieden said that his agency has spent $194 million of the $222 million in federal funds set to fight the Zika virus and that if Congress did not budget more money to fight the disease. (Photo by Chip Somodevilla/Getty Images)