Joe Biden, U.S. vice president, joked in Athens that Washington could make "more money" to help Greece out of the crisis.

During the meeting with Greek President Karolos Papoulias, Biden presented one of its delegates in this way: "This man is the Treasury Department. He brought hundreds of millions of dollars. "The comment prompted laughter from the Greek and American officials present.

At the press conference before meeting with Prime Minister Lucas Papademos, Biden said the U.S. would support Greece "in these difficult times", without specifying concrete measures to help.

"We are ready to help as we can," said the U.S. official, quoted by Reuters. In turn, Papademos said he was confident that Athens can count on U.S. support.

European leaders will meet Friday in Brussels at a EU summit considered crucial for the future of the euro area. Europe could turn to the IMF for proper emergency fundraising, according to scenarios circulating in the international press.