By Renee Maltezou

ATHENS (Reuters) - Greece hopes that a visit by U.S. President Barack Obama that begins on Tuesday will increase pressure on its creditors to grant debt relief to an economy shattered by years of recession.

The United States and the International Monetary Fund have urged a restructuring of Greece's crippling debt load but face resistance from the European Union, particularly Germany, whose banks would be most exposed to such a move.

Obama, on his last trip to Europe before handing power to Donald Trump in January, will discuss the debt issue and the continent's migrant crisis with Prime Minister Alexis Tsipras, but his visit will also trigger protests by leftist groups and trade unions that have long seen the United States as an "imperialist" power.

"U.S President Barack Obama's visit is of paramount importance," said government spokesman Dimitris Tzanakopoulos.

"I believe he wants to conclude his eight-year presidency with solutions on a series of issues on foreign and economic policy."

In an interview with Kathimerini newspaper on Sunday, Obama said he would "continue to urge Greece's lenders to take the necessary steps to ensure that Greece is in a position to return to healthy economic growth, including granting it essential debt relief".

Greece has adopted tough austerity measures in exchange for three international bailouts over six years, but has now pinned its hopes for a recovery on debt relief. At 177 percent of national output, its debt is still the highest in the euro zone.

Tsipras' government, which is trailing in the opinion polls, hopes that debt relief will help convince angry voters that their sacrifices are paying off.

PROTESTS PLANNED

Labor unions are planning demonstrations during Obama's visit against U.S. policy in Syria, past U.S. actions in Greece and the austerity measures of their own left-led government.

"Obama is coming as an agent of imperialist interests," Greece's public sector union ADEDY said in a statement.

It described Obama's visit, three days before the anniversary of a bloody student revolt in 1973 that helped topple Greece's U.S.-backed military junta, as a "provocation".

Police have banned public gatherings in a large swathe of central Athens during the visit, excluding an area where protesters typically gather for demonstrations. The protesters are also scheduled to march toward the U.S. embassy.

Obama, who will travel to Berlin after his two-day stopover in Athens, is the first serving U.S. president to visit Greece since Bill Clinton in 1999.

Greeks, like other Europeans, are reticent about how relations with the United States will develop under Trump, a billionaire businessman with no previous experience of public office. Trump has criticized the NATO alliance and said European nations should spend more on their own defense.

(Editing by Michele Kambas and Gareth Jones)