WASHINGTON -- President Bush on Wednesday signed a congressional resolution authorizing war against Iraq, and told Prime Minister Ariel Sharon that Israel has a right to retaliate if Saddam Hussein strikes his nation without provocation.

"If Iraq attacks Israel tomorrow, I would assume the prime minister would respond," Bush said in remarks that created confusion about his expectations for Israel if America goes to war. "He's got a desire to defend himself."

In a flurry of activity, Bush tried to use Sharon's visit and the vote of support in Congress to ease opposition at the United Nations for a tough new anti-Iraq resolution. He warned France, Russia, China and other balking allies that Saddam poses a grave threat to their security.

"Those who choose to live in denial may eventually be forced to live in fear," the president said as the United Nations opened two days of contentious debate over his Iraqi plans. In an East Room ceremony to sign the war-making resolution, Bush also said it's time to "fully and finally" disarm Iraq and remove Saddam from leadership.

After a lengthy meeting with Sharon, the president was asked whether he wanted Israel to refrain from retaliating if Iraq attacks in response to a U.S.-led war. Bush's father persuaded Israel to hold its fire during the 1991 Persian Gulf War.

Sidestepping the question, Bush said: "First of all, I have told the prime minister that my hope is that we could achieve disarmament of the Iraq regime peacefully."

On a follow-up question, Bush said he was discussing the proper response to an immediate, unprovoked attack on Israel. "If Iraq were to attack Israel tomorrow, I'm sure there would be an appropriate response."

Not a green light

White House officials hastily tried to clarify Bush's remarks, saying he was not giving Israel a green light to retaliate if Iraq attacks in response to U.S. action.

In a war situation, the United States would consult Israel, spokesman Ari Fleischer said. "That is a separate issue from, if Iraq tomorrow launched an attack unprovoked, whether they would have a right to defend themselves," the spokesman said.

Fleischer would not say whether Bush asked Sharon to hold his fire if attacked by Iraq amid a U.S.-led war.

However, a senior administration official, speaking on condition of anonymity, said Sharon would be asked to "understand how we can work together to achieve our big-picture goals" -- a subtle but unmistakable signal that the United States would prefer that Israel not retaliate.

Flanked by Vice President Dick Cheney and Secretary of State Colin Powell, Bush signed the resolution giving him power to use force against Saddam, if necessary.

The vote was 296-133 in the House and 77-23 in the Senate for the measure allowing Bush to take action against Iraq regardless of sentiments at the United Nations. Bush has threatened to build a coalition of allies outside the United Nations to confront Saddam.

"The time has arrived once again for the United Nations to live up to the purposes of its founding: to protect our common security," Bush said. "The time has arrived once again for free nations to face up to our global responsibilities and confront a gathering danger."

At the United Nations, Secretary-General Kofi Annan backed a new U.N. resolution that would toughen weapons inspections and urged Baghdad to use this "last chance." But leaders from 130 mainly developing countries demanded a peaceful settlement of the U.N. dispute with Iraq.

South Africa's U.N. Ambassador Dumisani Kumalo, whose country chairs the movement, urged the council to "seize the possibility of a peaceful solution."

As if in reply, Deputy Defense Secretary Paul Wolfowitz told military experts in Washington that the United States can't "be hamstrung by the waverings of the weak."