By David Alexander
WASHINGTON (Reuters) - Iran still has a peaceful way out of the growing confrontation over its nuclear program, the White House said on Wednesday, but a spokesman would not confirm reports that President Barack Obama wrote to Iranian leaders expressing a readiness to talk.
White House spokesman Jay Carney said Iran should engage major powers in discussions about its nuclear work, which the United States and many other countries say is intended to build a nuclear weapon, as European Union foreign policy chief Catherine Ashton outlined in a letter in October.
"If the Iranians are serious about restarting talks, then they need to respond to that letter," Carney told a White House briefing. "That is the channel by which ... the restarting of those talks would take place."
Carney declined to confirm reports from Tehran that Obama had sent Iranian leaders a new letter about talks, but did not deny a letter had been sent. Direct communications between the U.S. and Iranian governments, which have no diplomatic ties, are rare.
"We don't discuss specific ... diplomatic communications," he said, adding that anything said privately to Tehran would be consistent with what the United States has said publicly.
Earlier, Iranian politicians said Obama had expressed readiness to negotiate in a letter to Tehran. Iran's foreign minister said discussions were under way on reopening talks, but the EU denied this.
Still, after weeks of mounting pressure and new U.S. and European sanctions that target Iran's oil exports, the Obama administration appeared Wednesday to be emphasizing a diplomatic strategy on Iran's nuclear program, which Tehran says is for generating electricity.
The EU is preparing to intensify sanctions against Tehran with an embargo on Iran's oil exports and possibly freezing the assets of Iran's central bank. Obama is preparing to implement new U.S. sanctions that target foreign financial institutions that do business with Iran's central bank.
Iran has threatened to close the strategic Strait of Hormuz, through which much of the region's oil flows, in response to any embargo. U.S. officials have warned that closure of the strait would provoke an American reaction.
Any step Obama takes toward talks with Iran is almost certain to generate criticism from his Republican presidential rivals and hawks on Capitol Hill.
Obama, in an interview with Time magazine on Wednesday, rejected criticism from leading GOP candidate Mitt Romney and reiterated his pledge to "take every step available to prevent Iran from obtaining a nuclear weapon."
"Can we guarantee that Iran takes the smarter path?" he asked. "No, which is why I've repeatedly said we don't take any options off the table in preventing them from getting a nuclear weapon."
Obama's Republican critics condemned the prospect of renewed talks with Iran, highlighting the danger the Democratic president faces of appearing weak in his dealings with Iran during an election year.
"I think it's very difficult to have talks with a country around the world who's vowed to do everything but wipe us off the face of the Earth," said John Boehner, the speaker of the House of Representatives.
"This is not the kind of environment that I believe could lead to constructive discussions," he added. "And in fact, I do think it makes America look weak."
Representative Ileana Ros-Lehtinen, who chairs the House Foreign Affairs Committee, said that during a visit to the Middle East last week, leaders seemed to think the United States was on the verge of new talks with Iran.
"I certainly hope we are not going to do that foolish venture again," she said. "We've done that ? it didn't work then, it's certainly not going to work now. To reward them with conversations after they've been so belligerent as of late is counterproductive."
(Additional reporting by Susan Cornwell and Alister Bull; Editing by Warren Strobel Doina Chiacu)