SINGAPORE -- Stronger penalties are needed against Iran "not next year or the year after, but right now" because of the uncertainty over how soon Tehran may acquire a nuclear weapon, President Bush's defense secretary said Saturday.

Pentagon chief Robert Gates did not rule out military action to stop Iran's program, though he said it was an unattractive option.

"Probably everybody in this room wants there to be a diplomatic solution to this problem," he told an international audience of military officers, government officials and private security experts.

Asked about U.S. intelligence estimates of Iran's progress toward getting nuclear arms, Gates said, "Having to take care of this problem militarily is in no one's interest."

Yet uncertainty about Tehran's nuclear work, he said, "does put a premium on unanimity in the international community -- especially in the U.N. Security Council -- in terms of ratcheting up the pressure on the Iranians, not next year or the year after but right now."

The council has ordered two rounds of penalties over Iran's nuclear program.

Secretary of State Condoleezza Rice said Friday the United States was not preparing for war against Iran. But Vice President Dick Cheney last month stood on the deck of an aircraft carrier in the Persian Gulf and warned Tehran that Washington would prevent the Islamic republic from dominating the Middle East.

Gates said the "general view" among U.S. intelligence analysts is that Iran could develop a nuclear device "probably sometime in the period 2010-2011 or 2014 or 15."

"The reality is that because of the way Iran has conducted its affairs we really don't know," making it even more urgent to strengthen economic penalties in hopes of forcing Iran to change course, Gates said.

Secretive development

U.S. intelligence agencies have had trouble estimating the state of foreign nuclear programs, mainly because of their secretive development.

Iraq was a stark example. Before U.S. forces invaded in 2003, the CIA asserted it was likely that Iraq was reconstituting a nuclear program set back by the 1991 Gulf War. It turned out that Iraq had no active nuclear program and no other programs involving weapons of mass destruction.

Iran insists its nuclear program is intended to develop nuclear power as an energy source. The Bush administration rejects that explanation.

The dispute is complicated by other sources of tension between Washington and Tehran, including Bush's assertion that Iran is supplying arms to insurgents in neighboring Iraq.

Iran was not represented at the conference, held each year to exchange views on security issues affecting the Asia-Pacific region. Iran was not a central focus of the conference. But it was the subject of the first question put to Gates after he delivered a prepared address offering assurances the United States would remain an Asia power.

For the first time, China chose to send a senior official, Lt. Gen. Zhang Qinsheng, who offered a pointed defense of his country's military buildup and said it was strictly for self-defense.

In response to a question from former U.S. defense secretary William Cohen, Zhang said China expects a final agreement in September on a long-standing U.S. proposal for a "hot line" between American and Chinese defense leaders for use during crises.

Some of the questions for Gates dealt with the fight against terrorism.

Asked whether the United States and its allies are winning, Gates said it was too early to say. He called for more focus and progress on combating poverty and other problems that he said are underlying causes of extremism.

"I think we are still early in this contest," Gates said.

He cited areas of progress, including the elimination in late 2001 of Afghanistan as a haven for al-Qaida. But he also said the Islamic extremists have managed since then to expand their recruiting grounds.

"On the negative side of the ledger, I think we have not made enough progress in trying to address some of the root causes of terrorism in some of these societies, whether it is economic deprivation or despotism that leads to alienation," he said.

"One of the disturbing things about many of the terrorists that have been caught is that these are not ignorant, poor people," he said. "These are educated people, often from professional families. So dealing with poverty and those issues is not going to eliminate the problem, but it certainly can reduce the pool of people prepared to give their lives for this cause."