U.S. Senator John McCain, a former prisoner of war in Vietnam who ran for president in 2008, died on Saturday. He was 81.

An Arizona senator for more than three decades, McCain had been in the public eye since the 1960s when, as a naval aviator, he was shot down during the Vietnam War and tortured by his North Vietnamese Communist captors.

McCain backed gun control and voted for liberal positions on immigration.

President Trump has tweeted his “deepest sympathies and respect” to McCain’s family.

German Chancellor Angela Merkel said, “John McCain was guided by the firm conviction that the value of all political work could be found in serving freedom, democracy and the rule of law.”

French President Emmanuel Macron called McCain “a true American hero (whose).. voice will be missed”.

British Prime Minister Theresa May said he “embodied the idea of service over self.”

World Economic Forum founder and executive chairman Klaus Schwab said, "a great friend of the Forum has passed away and the world will miss a leading statesman who throughout his life showed incredible courage and passion in defending the values that we share".