The European Union formally adopted an oil embargo Monday against Iran and a freeze of the assets of the country's central bank, the Associated Press reported. Diplomats said the measures, which were adopted in Brussels by the EU's 27 foreign ministers, include an immediate embargo on new contracts for crude oil and petroleum products, while existing contracts will be allowed to run until July. British Foreign Secretary William Hague called the embargo part of "an unprecedented set of sanctions." "I think this shows the resolve of the European Union on this issue," Hague said. The EU also agreed to freeze the assets of the Iranian central bank. German Foreign Minister Guido Westerwelle said it was critical that action be taken. "This is not a question of security in the region," he said. "It is a question of security in the world."