Greek media reports say the prime minister has cancelled his trip to the United States because of the gravity of his country's financial crisis.
George Papandreou, who had left for London en route to New York, will return to Greece tonight.
State TV NET and private Mega Channel, citing unidentified government sources, said Papandreou had decided to return following a consultation with Finance Minister Evangelos Venizelos.
Papandreou had been scheduled to attend the UN General Assembly and then the annual meeting of the International Monetary Fund, where he was to meet managing director Christine Lagarde and US Treasury Secretary Timothy Geithner.