LONDON -- U.S. Secretary of State Hillary Rodham Clinton is using meetings in London this week to press ahead with imposing tough new international sanctions on Iran over its nuclear program.

A senior U.S. official said Wednesday that Clinton would raise the prospect of new U.N. Security Council sanctions against Iran in discussions with the foreign ministers of Russia, China, Britain, Germany, France, Italy, Indonesia, Saudi Arabia and the United Arab Emirates.

The official spoke on condition of anonymity because the meetings will be private. Clinton and her colleagues are in London for British-hosted meetings this week on Yemen and Afghanistan.