"We are glad they are going back to the EU-3 talks and we hope that they produce productive results," spokesman Tony Snow told reporters at a briefing.

His remarks came as Britain, France and Germany sought to reopen negotiations on halting the Islamic republic's uranium enrichment, which the West fears could be diverted into materials for making nuclear weapons.

The Bush administration's remarks welcoming the talks came after a White House spokeswoman earlier Tuesday expressed skepticism over remarks by Iran's foreign minister Manouchehr Mottaki that his country was willing to restart talks with the European Union immediately over Tehran's nuclear program.

Snow said that despite the optimism, the White House still feels that caution is warranted when dealing with Iran.

"Trust but verify," the spokesman said. "We'll just have to wait and see."

He added: "The first thing we've got to do is get a change of Iranian behavior," adding that in the past, "there have been a number of occasions where the Iranians have signaled some willingness to negotiate and then they pulled the rug out."

"They have to demonstrate not only good faith in negotiations, but good behavior, and we haven't seen any of that yet," Snow said.

Britain, France and Germany assembled a package of trade and other incentives aimed at coaxing Iran into agreeing to halt uranium enrichment.

But Mottaki, who is in Malaysia for a gathering of nonaligned countries, ruled out the prospect of negotiations with the United States.

Washington suspects Iran is working secretly toward building its own nuclear weapons under cover of a civilian drive for atomic power.