US intelligence services spied on at least 38 foreign embassies and missions, including those of allies, according to the latest secret documents leaked by National Security Agency whistle-blower Edward Snowden.
It collected information with bugging devices, tapped cables and specialised antennas, the documents showed.
Among the sites listed on one document as "targets" are the European Union's missions in New York and Washington.
Along with traditional ideological adversaries and sensitive Middle Eastern countries, the list of targets also includes the French, Italian and Greek embassies, as well as those of a number of other American allies, including Japan, Mexico, South Korea, India and Turkey. The list in the September 2010 document does not mention Britain or Germany.
One of the bugging methods mentioned is codenamed Dropmire, which, according to a 2007 document, is "implanted on the Cryptofax at the EU embassy, DC" - an apparent reference to a bug placed in a commercially available encrypted fax machine used at the Washington mission. The NSA documents note the machine is used to send cables back to foreign affairs ministries in European capitals.
The documents suggest the aim of the bugging exercise against the EU embassy in Washington is to gather inside knowledge of policy disagreements on global issues and other rifts between member states.
The new revelations come at a time when there is already considerable anger across the EU over earlier evidence provided by Snowden of NSA eavesdropping on America's European allies. Germany's justice minister, Sabine Leutheusser-Schnarrenberger, demanded an explanation from Washington, saying that if confirmed, US behaviour "was reminiscent of the actions of enemies during the cold war".
The German magazine Der Spiegel reported at the weekend that some of the bugging operations in Brussels targeting the EU's Justus Lipsius building - a venue for summit and ministerial meetings in the Belgian capital - were directed from within Nato headquarters nearby.
The US intelligence service codename for the bugging operation targeting the EU mission at the United Nations is "Perdido". Among the documents leaked by Snowden is a floor plan of the mission in midtown Manhattan.