The United States appeared to set a deadline Friday for Iran to ease world concern over its disputed nuclear program, as Secretary of State Hillary Rodham Clinton said the Islamic republic must act by this month's talks with world powers in Moscow.

Speaking in Norway's capital, Clinton told reporters the U.S. would continue down the path of negotiations alongside Britain, China, France, Germany, Russia and the United Nations. They all are trying to force Tehran to halt enrichment of uranium that could be used in nuclear weapons.

The standoff has stretched for almost a decade, though two recent rounds of talks in Istanbul and Baghdad left negotiators more optimistic that some sort of breakthrough could be reached. The diplomatic activity is occurring against a backdrop of deepening U.S. and Israeli concerns, with neither party willing to take the threat of military action against Iran off the table.

"Our negotiations with Iran have never been about intentions or sincerity, but about actions and results," Clinton said after meeting top Norwegian officials.

She said the U.S. needed to see "concrete actions" at the talks in Russia's capital, which are set to begin June 17.

"We will know by the next meeting in Moscow in a few weeks whether Iran is prepared to take those actions," she said. "There are lots of concerns that we continue to have about their intentions, but we will judge them by their actions. And we will determine whether those actions are sufficient to meet their obligations."