sanctions

VIENNA (Reuters) - A senior U.S. official said on Thursday Russia and China had been blocking tough U.N. sanctions against Iran for months but there would be a push to impose them if Tehran had not suspended nuclear activity within two weeks.

The United States targeted three of Iran's largest banks Thursday, cranking up pressure on Tehran for its alleged nuclear weapons drive and terrorist financing. "Iran exploits its global financial ties to pursue nuclear capabilities, develop ballistic missiles and fund terrorism," Treasury Secretary Henry Paulson said.