U.S. Secretary of State Condoleezza Rice is urging the U.N. Security Council to impose sanctions on Iran immediately, saying the Tehran government must be held accountable for its defiance regarding the nation's nuclear program. Secretary Rice says Iran is closely watching the world's reaction to North Korea's recent nuclear test, and says weapons programs in both countries will never bring them prestige or more security.

Secretary Rice says it is time for action on Iran's nuclear program.

"The United Nations Security Council is now working on an Iran sanctions resolution. For the international community to be credible, it must pass a resolution now that holds Iran accountable for its defiance," she said.

Secretary Rice made the remarks in a speech at the Heritage Foundation, a Washington-based public policy institute.

She says Iran should pay close attention to the wide-ranging sanctions being imposed on North Korea since it carried out its first test of a nuclear weapon earlier this month.

"The greatest challenge to the non-proliferation regime comes from countries that violate their responsibilities under the Non-Proliferation Treaty," she added. "The North Korean government has been one such case, so is Iran. The Iranian regime is watching how the world responds to North Korea's behavior and it can now see the international community will confront this threat. Iran can see that the path North Korea is choosing is not leading to more prestige and more prosperity or more security. It is leading to just the opposite."

Western nations fear Iran's uranium enrichment program could allow the Islamic republic to make nuclear weapons. Teheran insists its program is solely aimed at generating electricity.

Secretary Rice also urged North Korea to return to talks regarding incentives being offered if Pyongyang abandons its efforts to build nuclear weapons.

"North Korea shouldlive up toits own international agreements to de-nuclearize and it should pursue policies that are not hostile to its neighbors and hostile to international principles and norms of behavior," she said. "Everything North Korea says that it seeks is on the table in the six-party talks."

The six-party process, which includes the United States, North Korea, China, South Korea, Japan and Russia, began in 2003, but has been stalled for more than a year because of a boycott by Pyongyang.

Secretary Rice recently wrapped up a trip to the region where she sought support for the U.N. sanctions against North Korea.