On the last leg of his final European tour as the US president, Barack Obama has landed in Berlin to meet with German Chancellor Angela Merkel, with whom he has established a close friendship during his time in office.

White House officials said on Wednesday that during his meeting with Merkel, the outgoing US president will highlight shared values, thank the German chancellor for her friendship during his eight years in office, and try to ease concerns about the future of a transatlantic partnership that President-elect Donald Trump may now call into question.

Obama, who ahead of the visit called Merkel his "closest international partner", was hosted for a dinner by the chancellor at Berlin's famous Adlon hotel on Wednesday evening.

The US leader will hold talks with Merkel at the German Chancellery in Berlin on Thursday, and will hold another meeting on Friday when he is also scheduled to meet with the leaders of Britain, France, Italy and Spain.

Obama and Merkel, who took power three years before him, developed a strong partnership, despite rifts over revelations of the American spying agency NSA'd surveillance of Merkel and the US leader's strong opposition to Germany's response to the European debt crisis.

Obama began his last official overseas trip of three nations on Tuesday with Greece where he held meetings with President Prokopis Pavlopoulos and Prime Minister Alexis Tsipras, as he seeks to calm the nerves of allies concerned by Trump’s election victory.

The US president will conclude his tour with a stop in the South American nation of Peru for a summit of the Asia-Pacific Economic Cooperation forum (APEC).

Speaking in Athens on Wednesday, Obama warned that globalization required a "course correction" to keep voters from drifting to extremism, referring to the rise of extremist politics both at the US and Europe.

"When we see people, global elites, wealthy corporations seemingly living by a different set of rules, avoiding taxes, manipulating loopholes... this feeds a profound sense of injustice," he said.

Last week, Republican presidential candidate Trump stunned the world by defeating the heavily-favored Democratic candidate, Hillary Clinton, in the November 8 election, despite the fact that his campaign had been hit with many controversies since its inception in early 2015.

After Trump's triumph, Merkel expressed a desire to maintain close relations with the United States, but pointedly said bilateral cooperation must be based on shared democratic principles and respect for human dignity, hinting at the New York billionaire’s divisive rhetoric against women, Muslims, immigrants and other minorities.