The leaders of France and Germany took aim yesterday at the US over media reports that its intelligence services had spied on European diplomats, raising questions about the future of a landmark EU-US trade deal.

“Spying on your friends is unacceptable,” the spokesman for German Chancellor Angela Merkel, Steffen Seibert, said in Berlin. “It can’t happen. We are no longer in the Cold War.”

“We demand that this stops immediately,” French President Francois Hollande said during a visit to the western city of Lorient. “We cannot accept this type of behaviour.”

The allegations are the latest stemming from former intelligence contractor Edward Snowden, who has disclosed information about US surveillance programmes to various news outlets.

The British newspaper the Guardian wrote yesterday about a September 2010 document from the US National Security Agency (NSA) that listed 38 embassies and missions as “targets” for surveillance.

Those spied on included EU delegations in New York and Washington and the French, Italian and Greek embassies. US allies including South Korea, Japan, Mexico and India were also spied upon alongside traditional foes and some Middle Eastern countries.

The surveillance of the European Union was apparently aimed at gathering information on disputes between member states.

Italy’s relations with the US “would be strongly compromised” if the allegations were proven true, Italian Defence Minister Mario Mauro told the La Repubblica daily.

The US has promised to give “clarifications” to the EU and its member states, Italian Foreign Minister Emma Bonino said.

The bugging of the EU offices had also been reported over the weekend by the German magazine Der Spiegel, which additionally wrote that the NSA had conducted a wiretapping operation of the bloc in Brussels for more than five years.

“These are disturbing news if proven true,” the EU’s executive, the European Commission, said in a statement. “They demand full clarification. Clarity and transparency is what we expect from partners and allies, and this is what we expect from the US.”

US Secretary of State John Kerry said such activities were not unusual.

“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, and all I know is that is not unusual for lots of nations,” he said in Brunei at a meeting of the Association of Southeast Asian Nations.

Kerry met EU foreign policy chief Catherine Ashton on the sidelines of the event and said: “I agreed to find out exactly what the situation is and I would get back to her.”

The US ambassadors in Germany and France were also due to have consultations with those countries’ foreign ministries.

European Commission President Jose Manuel Barroso, meanwhile, has instructed services from his institution to carry out “a comprehensive ad-hoc security sweep and check” to look for signs of spying and eavesdropping, spokeswoman Pia Ahrenkilde said.

At the same time, EU officials cautioned that the new allegations appear to date back to 2010 and 2007.

The EU delegation in Washington changed buildings in 2010 while the New York delegation moved in 2012, foreign affairs spokesman Michael Mann noted.

Relations between the EU and US had already become tense after previous leaks suggested that the NSA might have targeted European citizens with its surveillance programmes.

The debacle came just as the two partners were set to launch negotiations on a free trade deal, which has been hailed as a potential source of growth and jobs for the crisis-beleaguered EU. The first round of talks was supposed to take place July 8.

Ahrenkilde declined to comment on whether it could now be delayed.

“We are focused on the issue at hand, which means clarification from our American partners,” the spokeswoman said.

“If we are friends, if we are allies, it is honestly not acceptable that within this relation we have a behaviour more akin to the relationship that the Soviet Union once had with its satellite countries than to relationship between the US and allied countries,” Mauro was quoted as saying by La Repubblica.

“Trust must be the basis of our co-operation, and confidence must be restored on this matter,” Seibert said.

Germany has been particularly troubled after the leaked documents showed that it was targeted far more than other EU countries and was classed by the US as a “third-class” partner and, therefore, in the same spying category as China, Iraq and Saudi Arabia.

“It’s beyond belief that our friends in the US see Europeans as the enemy,” German Justice Minister Sabine Leutheusser-Schnarrenberger said.