Hollande's call comes a day after France and Germany reacted furiously to reports that US had used covert surveillance to keep tabs on the French envoy in Washington, DC as well as offices for the European Union.

"Europe must have a coordinated, common position on the requirements we need to come up with and the explanations we must ask for," Hollande said as he met his Lithuanian counterpart Dalia Grybauskaite, whose country currently holds the EU presidency, in Paris.

The latest revelations attributed to fugitive former CIA operative Edward Snowden have threatened to derail free trade talks between the US and the EU just as they were set to begin.

Hollande believes EU nations must decide on a common position before those talks place.

European Justice Commissioner Viviane Reding has already said the trade talks could be in jeopardy.

The EU could not negotiate "if there is any doubt that our partners are bugging the offices of European negotiators", she said.

European Commission chief Jose Manuel Barroso's office said he had ordered a full security sweep of all its premises worldwide.

And one European Union source said officials could not simply brush the allegations aside.

"This goes far beyond the requirements of national security," said the official, speaking on condition of anonymity.

"It is a breach of trust and we are at the beginning of something very serious."

Germany and France both said the US ambassadors to their countries had been invited to discuss the issue.

On Monday, the French president said Paris had demanded answers from Washington about reports that the US National Security Agency (NSA) bugged European offices and embassies.

"We cannot accept this kind of behaviour between partners and allies," he told journalists during a visit to the western city of Lorient.

"We ask that this immediately stop," he added.

Later on Monday US Secretary of State John Kerry tried to smooth over the row, saying he was looking into allegations but he also suggested that the spying was business as usual.

"I will say that every country in the world that is engaged in international affairs, of national security, undertakes lots of activities to protect its national security and all kinds of information contributes to that," he said.

"All I know is that is not unusual for lots of nations," he added, declining further comment until he had all the facts.

Hollande also said France had not received an official request for asylum from Snowden, the former NSA contractor behind the spying allegations.

Paris has "not yet received any particular request from Mr. Snowden," Hollande said, refusing to comment further.

WikiLeaks said Monday that Snowden had submitted asylum requests to 21 countries including France.