BRUSSELS: France and Germany pushed Friday for Washington to agree new rules on espionage after damaging revelations the United States tapped German Chancellor Angela Merkel's mobile phone and spied on other allies.
Paris and Berlin will "seek bilateral talks with the US" to reach an understanding by year's end on the conduct of intelligence gathering among allies, EU President Herman Van Rompuy told reporters after a first day of EU summit talks.
Van Rompuy said other countries could join if they wished.
In a statement, the 28 EU leaders "underlined the close relationship between Europe and the USA and the value of that partnership."
This partnership "must be based on respect and trust, including as concerns the work and cooperation of secret services," the Europeans stressed.
Britain has long-established intelligence ties with the United States but questioned on London's role, Van Rompuy stressed that all leaders had agreed on the text.
Britain "of course has a special relationship (with the United States) ... but they are completely on board with this text", he added.
Prime Minister David Cameron made no comment to waiting reporters.
Merkel had arrived at the two-day talks saying: "Spying between friends, that's just not done" after reports the US National Security Agency had eavesdropped her calls.
"We need trust between partners and such trust needs to be re-established," she said.
The summit was meant to discuss boosting employment and the digital economy but was quickly overtaken by the growing scandal which has embroiled US President Barack Obama in embarrassing exchanges with key allies -- from France and Germany to Brazil and Mexico.
More could follow after a fresh slew of damaging revelations, with Britain's Guardian daily saying Washington had listened in on the phone conversations of 35 world leaders.
Hollande and Merkel called Obama earlier this week demanding clarification of claims the NSA had spied on millions of French phone calls and on the German leader personally.
The French president called for a code of conduct, recalling that the EU had set up a special unit to review the issue after leaks by fugitive former US intelligence contractor Edward Snowden earlier this year.
These experts have to "accelerate their work with our American allies", Hollande said, because "this is a subject which is not going away".
"We need to get results," he said, adding that in the end, Snowden's revelations may prove useful.
Meanwhile, an advisor to President Obama acknowledged that US surveillance had created "significant" challenges with its allies.
"Though we collect the same sort of intelligence as all nations, our intelligence community has more restrictions and oversight than in any other country in history," Lisa Monaco, assistant to the president on homeland security and counterterrorism, wrote in an opinion article in American daily USA Today.
Recent disclosures "have created significant challenges in our relationships with some of our closest foreign partners," Monaco said.
Monaco added that "the president has directed us to review our surveillance capabilities, including with respect to our foreign partners."
In Washington earlier, White House spokesman Jay Carney told reporters: "We are not going to comment publicly on every specified alleged intelligence activity," noting that all nations spy on each other.
"We want the truth," said Italian Prime Minister Enrico Letta in Brussels, as leaders of Belgium, Finland, Malta and others said Washington must provide an explanation.
Letta had a particular interest in the issue after Italian weekly L'Espresso said Britain and the United States spied on Italy to glean data on underwater fibre-optic cables -- with the consent of Italy's own secret services.
The scandal has sparked widespread anger in Europe, with some senior EU officials suggesting talks on a massive EU-US free-trade agreement could be suspended.
Merkel, however, cautioned against such a move, arguing: "When you leave the room you have to work out how to get back."
The European Parliament has already asked for a key EU-US bank data-sharing deal aimed at fighting terrorism to be suspended.
The summit's second and final day of talks Friday is supposed to tackle an immigration crisis highlighted by the deaths of hundreds of desperate refugees trying to reach Europe's shores but the spying scandal could easily take the headlines again.