European allies are keen to hear from the outgoing US president on how Donald Trump is likely to see transatlantic ties.
US President Barack Obama arrived in Athens on Tuesday, the first stop on a final foreign trip that will aim to reassure worried Europeans following Donald Trump's surprise presidential election victory.
Opening a farewell visit to Europe, Obama will stop at the Parthenon, deliver a speech on the challenges of globalisation and meet Greek Prime Minister Alexis Tsipras and President Prokopis Pavlopoulos before heading to Germany on Wednesday.
Shortly after his arrival in Athens, where thousands of police officers have been deployed amid tight security in the capital, Obama will hold a joint press conference with the Greek prime minister.
Issues to be discussed with Greek leaders include the country's debt crisis and the refugee situation.
After travelling to Greece, Obama will head to Germany to meet Chancellor Angela Merkel, French President Francois Hollande and British and Italian prime ministers Theresa May and Matteo Renzi.
Trump's defeat of Hillary Clinton last week will be on everybody's minds as the future of several key global deals — on issues such as Iran's nuclear programme and the environment — looks uncertain.
During a press conference in Washington before his departure on Monday, Obama tried to reassure worried allies, stressing that dismantling or unravelling such agreements was not easy.
The outgoing US president will conclude his trip with a stop in Peru for a summit of the Asia-Pacific Economic Cooperation forum (APEC). Among the leaders he is expected to meet there is President Xi Jinping of China.