President Bush told the nation's pro-Israel lobby yesterday that the Jewish state "has every right to defend itself from terror," as the administration softened its opposition to an Israeli incursion into Gaza that has killed a score of Palestinians.

The president, whose speech to the American Israel Public Affairs Committee (AIPAC) was interrupted 67 times by applause and chants of "Four more years," delivered mild criticism of Israel's actions in Gaza. "The unfolding violence in the Gaza Strip is troubling and underscores the need for all parties to seize every opportunity for peace," he said.

Bush's statement was an indirect mention of the events in Rafah, in the Gaza Strip, where Israeli forces moved troops, helicopters and tanks yesterday into a densely populated Gaza refugee camp. The operation, which a Palestinian hospital official said killed 19 Palestinians, was one of the deadliest in the occupied territories in years.

Bush's description of Israel's actions was at odds with the position taken by Secretary of State Colin L. Powell. Speaking in Jordan on Sunday, Powell said: "We know that Israel has a right for self-defense, but the kind of actions that they are taking in Rafah -- the destruction of Palestinian homes -- we oppose." He said "we don't think that is productive" and emphasized that "the United States is anxious to do everything that it can to stop this cycle."

Bush instead emphasized that Israel is free to fight terrorism. "The United States is strongly committed, and I am strongly committed, to the security of Israel as a vibrant Jewish state," he said. "Israel is a democracy and a friend and has every right to defend itself from terror."

Bush's position was close to that voiced Monday in Berlin by his national security adviser, Condoleezza Rice, who said only that house demolitions in Rafah were "a subject of conversation and a subject of concern." Palestinian officials said that in a meeting with Rice, Prime Minister Ahmed Qureia appealed to her for the Bush administration to use its influence with Israel to immediately stop the destruction of homes in Gaza.

White House press secretary Scott McClellan said that while the administration opposes destroying the homes of "innocent Palestinians," it has received assurances about the Gaza incursion from Israel. "They've made clear to us that these operations that they're conducting are aimed at stopping the smuggling of arms through tunnels in Gaza, and at preventing the distribution of those arms, not aimed at destroying homes," he said.

Participants at the AIPAC conference said they viewed Bush's speech as an endorsement of Israel's actions. The 4,500 delegates at the Washington Convention Center gave the president thunderous ovations. An AIPAC spokesman said the group is nonpartisan and pointed out that President Bill Clinton received a similar reception and chant of "Four more years" during his first term.

AIPAC's president, Amy Friedkin, praised Bush for sidelining Palestinian leader Yasser Arafat. "You understood with great moral clarity the true nature of the man," she said.

Bush, when he began his speech, said of Friedkin: "Finally, AIPAC elected a president I can kiss."

The enthusiastic reception was a boost for Bush, who has sought with his unstinting support of Israel to lure Jewish voters and donors from their traditional home in the Democratic Party. Bush's Democratic opponent, Sen. John F. Kerry (Mass.), issued a statement that, without mentioning the Gaza violence, criticized Bush for not challenging Saudi Arabia's Crown Prince Abdullah for blaming a terrorist attack in that country on "Zionists."

"President Bush has said nothing," Kerry said. "As president, I will never permit this kind of attack to go unanswered."

In his speech to AIPAC, Bush again embraced Israeli Prime Minister Ariel Sharon's plan for a unilateral withdrawal from Gaza in exchange for assurances from the United States that it need not take back Palestinian refugees or return to its pre-1967 borders. Sharon's plan has been stalled by hard-liners in his own Likud Party, and violence has worsened in Gaza, where Israel has amassed forces after Palestinians killed 13 Israeli soldiers last week.