A campaigner attaches American flags to a 'Stop Trump' open-top double decker bus before touring London to urge Americans living abroad to register and vote, Britain September 21, 2016. REUTERS/Stefan Wermuth

U.S. President Barack Obama meets with Israeli Prime Minister Benjamin Netanyahu in the Oval office of the White House in Washington November 9, 2015. REUTERS/Kevin Lamarque

Nigel Farage, resigning leader of the United Kingdom Independence Party (UKIP) and Member of the European Parliament, addresses journalists during a press briefing at the European Parliament in Strasbourg, France, July 6, 2016. REUTERS/Vincent Kessler

The logo of Exxon Mobil Corporation is shown on a monitor above the floor of the New York Stock Exchange in New York, New York, U.S. December 30, 2015. REUTERS/Lucas Jackson/File Photo

A view of the swollen Yellowstone River two miles down stream from the site of the oil spill in Laurel, Montana, July 5, 2011. REUTERS/John Warner

Oil mixed with water from an oil spill along the Yellowstone River is pictured in Laurel, Montana, July 6, 2011. REUTERS/John Warner

The logo of Harley Davidson company is pictured on a motorcycle in Paris, France, May 8, 2016. REUTERS/Jacky Naegelen

A woman walks past a Camaieu women's clothing store in Paris, France, September 21, 2016. REUTERS/Jacky Naegelen