U.S. Secretary of State Hillary Clinton will seek clarification from Russia on its position if Washington and allies decide to press on with sanctions against Iran, a senior State Department official said on Monday, Reuters reported.

Clinton will hold talks with Russian Foreign Minister Sergei Lavrov and meet President Dmitry Medvedev on Tuesday.

"The secretary will want to speak to Foreign Minister Lavrov and President Medvedev about what specific forms of pressure Russia would be prepared for to join us and other allies if Iran fails to live up to its obligations," he told reporters.

Medvedev has said that sanctions could be the last resort if Iran failed to calm international suspicions it was seeking to obtain nuclear weapons, but has never committed Moscow to joining any specific sanctions.