U.S. Secretary of State Condoleezza Rice has defended new U.S. sanctions on Iran designating Tehran's Revolutionary Guard Corps as a proliferators of weapons of mass destruction and its elite Quds force as a supporter of terrorism in the Middle East.

In an interview Friday with NBC, Rice said the international community cannot sit idly by while it faces unpleasant choices.

Rice also told NBC the U.S. and Russia have some differences about the tactics and timing regarding Tehran, but said Washington and Moscow share the same basic goal of a non-nuclear Iran.

She said a nuclear weapon in the hands of Iran's leaders would deeply stabilize the world's most volatile region.

Russian President Vladimir Putin criticized the U.S. decision to impose the sanctions, saying they threaten to make the situation worse.

Iran said the sanctions violate international law and are "doomed to fail."

Rice said the decision to impose the sanctions Thursday was prompted by Iran's refusal to heed international demands that it drop what she called its nuclear weapons capability.  Iran has said its nuclear program is for peaceful purposes. 

The sanctions include measures aimed at isolating three Iranian state-owned banks and more than 20 Iranian entities, including individuals and companies.  The sanctions also cite the Quds force for allegedly providing material support to terrorist groups including Hezbollah in Lebanon and the Taliban in Afghanistan.

The measures mark the first time the U.S. has targeted another country's military with sanctions.