WASHINGTON (Reuters) - Democrat Hillary Clinton, under fire from rivals for a muscular attitude toward Iran, said on Monday “all options must remain on the table” if Tehran does not comply with nuclear nonproliferation requirements.

Democratic Presidential candidate and U.S. Senator Hillary Clinton, (D-NY) speaks outside Paschal's restaurant in Atlanta, Georgia, October 12, 2007. REUTERS/Tami Chappell

In an article for Foreign Affairs magazine, the Democratic presidential candidate said the United States should be prepared to offer incentives if Tehran ends its nuclear weapons ambitions, renounces sponsorship of terrorism, supports Middle East peace and plays a constructive role in stabilizing Iraq.

Oil-rich Iran denies trying to develop a nuclear weapon, saying its atomic program is for peaceful energy purposes. But the United States and its European allies believe Iranian President Mahmoud Ahmadinejad wants a nuclear bomb.

In the article, Clinton made a case for diplomatic talks with Tehran, saying “true statesmanship requires that we engage with our adversaries, not for the sake of talking but because robust diplomacy is prerequisite to achieving our aims.”

The New York senator said Iran poses a long-term strategic challenge to the United States, its NATO allies and Israel and accused the Bush administration of negligence in dealing with Iran.

However, she made clear that Iran “must not be permitted to build or acquire nuclear weapons.”

“If Iran does not comply with its own commitments and the will of the international community, all options must remain on the table,” Clinton wrote.

Her national security director, Lee Feinstein, told reporters in a conference call that Clinton was focusing on diplomacy in dealing with Iran, not military action, if she is elected president in November 2008.

The commander-in-chief, he said, “does not take options off the table,” but Clinton feels “the preferred approach right now is to pursue intensive diplomacy and economic pressure as the best way to avert a nuclear program in Iran and as the best way to avert a war.”

Clinton has been under fire from Democratic presidential opponents Barack Obama and John Edwards for voting for a Senate resolution recommending the State Department designate Iran’s Revolutionary Guards as a terrorist organization. They argued it could be used by the Bush administration to launch military attacks against Iran.

In the Foreign Affairs article, Clinton also said if elected she would direct U.S. military leaders to come up with a plan within 60 days of her inauguration to “bring our troops home” from Iraq in a way that begins to restore stability in the region and replaces military force with a new regional diplomatic initiative.

She said she would convene a regional stability group composed of key allies, other world powers and all states bordering Iraq to develop a strategy for achieving a stable Iraq that provides incentives for Iran, Saudi Arabia, Syria and Turkey to stay out of Iraq.

Clinton also said if elected she would seek to negotiate an agreement with Russia to substantially reduce U.S. and Russian nuclear arsenals to send a “strong message of nuclear restraint to the world.”

She described a pragmatic relationship with Russia.

She said Russian President Vladimir Putin had suppressed many of the freedoms won after the fall of communism, but added it would be a mistake to see Russia only as a threat.

Clinton said the United States should work with Russia on selective issues such as thwarting Iran’s nuclear ambitions, securing loose nuclear weapons in Russia and former Soviet republics and reaching a diplomatic solution in Kosovo.