Senior diplomats from the U.S., Russia and China will join representatives from Britain, France and Germany for the meeting. They will meet behind closed doors at the Foreign Office in Whitehall.

A British Foreign Office spokesman told Xinhua this is a "confidential diplomatic meeting" on Iran. He refused to give further details.

Tensions mounted last week after Iran resumed nuclear fuel research. But Tehran defended that it would not go as far as making weapons.

Britain, France and Germany have already started the moves to refer Iran to the United Nations Security Council for possible sanctions over Tehran's decision. They said that two-and-a-half years of efforts to resolve the issue had come to a "dead end."

European Union's foreign policy chief Javier Solana has insisted that the use of military action against Iran is currently"not in the mind of anyone."

On Sunday, Iran warned of soaring oil prices if sanctions were introduced.

For more than two years, Britain, France and Germany, with support from the International Atomic Energy Agency (IAEA), have been engaged in lengthy negotiations with Iran aimed at obtaining guarantees that it does not seek to develop nuclear weapons using the nuclear energy program as a cover.

The U.S. accuses Iran of running a covert nuclear arms program.Iran, however, has repeatedly said that its nuclear work is purely designed to meet its energy needs and insisted on the right to develop a full nuclear fuel cycle.