US President Barack Obama started his final scheduled foreign trip as president with a visit to the Greek capital Athens on Tuesday. He met with Prime Minister Alexis Tsirpas who is struggling with his country's national debt problems. Left-wing demonstrators held demonstrations against Obama's visit in which they threw firebombs at the hundreds of policemen providing security for the president. After Greece, Obama is to travel to Germany where he will meet with Chancellor Angela Merkel, who is considered very close to the American leader, as well as other senior German officials. The president will then fly to Peru where he is to participate in the Asia-Pacific Economic Cooperation summit including a meeting with his Chinese counterpart Xi Jinping. The main purpose of Obama's trip is to express support for Europe amid rising concerns and uncertainty regarding the policies of US President-elect Donald Trump, and amid the strengthening of right-wing extremist movements throughout Europe following the increase of terrorist attacks and the flood of refugees from the Middle East and Africa.