Obama arrives in Greece at start of his final foreign tour

Air Force One touched down midmorning in Athens after an overnight flight from Washington amid severe security measures that shut down major roads and banned public gatherings and demonstrations in swathes of central Athens and a southern suburb near a seaside luxury hotel where Obama was expected to stay.

Left-wing and anarchist groups have planned protest demonstrations for Tuesday afternoon, while an armed anarchist group has called for "attacks and clashes" to disrupt Obama's visit.

Obama's visit comes two days before the Nov. 17 anniversary of the junta's 1973 bloody crackdown on a student uprising, which is marked each year by a protest march to the U.S. Embassy which frequently turns violent.

"The visit of President Obama is a clear message to all of us and to the rest of the world that we need to keep pursuing policies that create growth, employment and social cohesion," Nikos Pappas, a close associate of Tsipras who was named digital policy minister in a recent reshuffle, told the AP ahead of the visit.

The government will also be looking for recognition of the country's role in Europe's refugee crisis, which saw hundreds of thousands of refugees pass through Greece from Turkey on their way to the more prosperous countries of the European north, and for U.S. pressure on the rest of Europe to help shoulder the burden.

Obama should "shine the spotlight not only on abysmal conditions for the tens of thousands of refugees stranded in Greece, but also on the failure of world leaders to adequately address the wider global refugee crisis," John Dalhuisen, Amnesty International's Europe director, said in a statement.