Former Secretary of State Henry Kissinger said the U.S. should negotiate directly with Iran over its nuclear program and other bilateral issues.

"One should be prepared to negotiate, and I think we should be prepared to negotiate about Iran," Kissinger, who brokered the end of the 1973 Yom Kippur war and peace talks with the North Vietnamese, said in an interview with Bloomberg Television. Asked whether he meant the U.S. should hold direct talks, Kissinger, 84, responded: "Yes, I think we should."

There has been no response so far from Iran, he said.

"I've been in semi-private, totally private talks with Iranians," he said. "They've had put before them approaches that with a little flexibility on their part would, in my view, surely lead to negotiations." He didn't elaborate on who was engaged in the talks.

While the Bush administration pursues a policy of diplomatic pressure on Iran at the United Nations and unilateral sanctions to weaken its access to the international banking system, the U.S. hasn't ruled out military action to halt Iran's nuclear work. There has been no direct contact between the U.S. and Iran since the 1979 Iranian revolution, except for talks in Baghdad on Iraqi security between their ambassadors or technical experts.

Iranian Foreign Minister Manouchehr Mottaki said March 9 that Iran wouldn't engage with the U.S. until President Bush's successor is elected.

Democratic presidential contender Sen. Barack Obama has said he would meet with U.S. adversaries such as the leaders of Iran without conditions, positions his primary opponent, Sen. Hillary Rodham Clinton, called "irresponsible and frankly naive."

The Republican candidate, Sen. John McCain, has said the Democratic candidates "won't recognize and seriously address" the threat from Iran's pursuit of nuclear weapons.

Iran maintains its enrichment of uranium is needed for nuclear power, while the U.S. says the project is cover for weapons development.

"It's not really the willingness to talk, it's so far the inability to define what we are trying to accomplish," Kissinger said. "The negotiations depend on a balance of incentives and penalties. Have we got those right at every point? Not at every point."

U.S. Defense Secretary Robert Gates announced three days ago that Adm. William Fallon would be stepping down as head of Central Command in the Arabian Gulf, provoking criticism that Bush won't tolerate dissent and feeding speculation his Iran policy could become more confrontational. Fallon once referred to tough White House rhetoric on Iran as "not helpful and not useful."

Kissinger's comments came on the eve of Friday's parliamentary voting in Iran. The United Principlist Front, allied to President Mahmoud Ahmadinejad, is competing for parliament's 290 seats against the Reformists' Coalition of his predecessor, Mohammad Khatami, and an emerging group, the Broad Principlist Coalition, which criticizes the president's handling of the nation's nuclear program and economy.

Polling times were extended by five hours and preliminary results will be published starting today. Almost 43 million people were eligible to vote.

The Nobel Peace Prize winner said any direct talks between the U.S. and Iran on issues such as the nuclear dispute would be most likely to succeed if they first involved only diplomatic staff and progressed to the level of secretary of state before the heads of state meet.