The warning followed a meeting on May 2 in London of senior officials from the five permanent members of the UN Security Council -- the United States, Britain, France, China and Russia -- plus Germany.
A British Foreign Office statement said the political directors from the six major powers agreed that a negotiated solution was still preferable, but that further action would be taken if necessary to get Iran to comply.
Earlier on May 2, President Mahmud Ahmadinejad said Iran would continue to resist attempts to curtail development of nuclear technology for peaceful, electric-generating purposes.
Also the same day, Ali Akbar Velayati, a foreign affairs adviser to Iranian Supreme Leader Ayatollah Ali Khamenei, said Tehran was capable of mass producing machines used for enriching uranium.
In a related development, Iranian authorities have arrested the country's former nuclear negotiator, Hossein Musavian. Few other details were available, but the semiofficial Fars news agency said Musavian could face espionage charges.
Meanwhile, a top U.S. diplomat says the United States is looking forward to talking to Iran at the international conference on Iraq in Egypt this week.
U.S. Undersecretary of State Nicholas Burns said in London on May 2 that Washington hopes that U.S. Secretary of State Condoleezza Rice would be able to speak directly to her Iranian counterpart at the Sharm el-Sheikh meeting.
Ties with Iran have been frozen since the 1979 storming of the U.S. Embassy in Tehran.
(Reuters, AP, AFP)
THE COMPLETE PICTURE: RFE/RL's complete coverage of controversy surrounding Iran's nuclear program.
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