President Bush is rebuffing calls for a cease-fire in the Middle East fighting and insisting that Israel is justified in using force to defend itself against rocket attacks and border incursions by Islamic militants in southern Lebanon.

“My message to Israel is that, as a sovereign nation, you have every right to defend yourself against terrorist activities,” Mr. Bush said yesterday during a meeting with Prime Minister Blair at the Group of Eight summit in St. Petersburg, Russia. “This started because Hezbollah decided to capture two Israeli soldiers and fire hundreds of rockets into Israel from southern Lebanon. That’s the cause of the crisis. And so our message to Israel is, look, defend yourself, but as you do so, be mindful of the consequences.”

Secretary of State Rice, who also is attending the summit in Russia, was more direct about the drawbacks of a cease-fire that leaves armed militants on Israel’s borders. “If you simply say, ‘Okay, let’s cease the violence,’ and it leaves the conditions in place that allow these extremists to launch these attacks in the first place, then I can assure you we will be back here three weeks from now or three months from now talking about another need for a cessation of violence,” she said on CBS’s “Face the Nation.”

Ms. Rice also said it was clear that Syria and Iran were involved in the recent attacks on Israel. “I absolutely see that Syria and Iran are playing a part in this. They’re not even trying to hide their hand,” she said.

During a briefing for reporters, Ms. Rice said no back-channel pressure is being applied to urge Israelis to stop their campaign. “We’re saying to the Israelis privately precisely what we’re saying to them publicly,” she said.

Mr. Bush’s decision to back Israel in the current fighting in the Middle East has drawn widespread support from American politicians, even as some in both parties questioned the administration’s broader policies in the region.

“Because of our lack of a prevention strategy, we’re left with no option here, in my view, but to support Israel in what is a totally legitimate self-defense effort,” Senator Biden, a Democrat of Delaware, said on NBC’s “Meet the Press.”

Mr. Biden, the ranking Democrat on the Senate Foreign Relations Committee, coupled his support for Israel with a withering critique of Mr. Bush.

“I don’t believe the president has a Middle East policy,” the senator said. “This idea that we go in and behead the monster named Saddam, somehow things are going to fall in place, I think was naive in the extreme, and we’re paying a very heavy price for it.”

A Republican who formerly served as House speaker, Newt Gingrich, rejected calls for Israel to halt its shelling. “I don’t think that any realistic person who’s being fair about this is going to focus on Israel,” he told NBC.

However, Mr. Gingrich also faulted the Bush administration for doing too little to aid Lebanon’s fledgling democracy following elections last year. “There has been a continuing failure of opportunity to strengthen the Lebanese government. There’s been a failure of opportunity to train and … reinforce the Lebanese army,” he said.

Mr. Gingrich also sharply criticized the administration’s policies on Iran and North Korea as too weak.

A secretary of state under President Clinton, Madeleine Albright, complained yesterday that restarting the “peace process” has been a low priority for administration officials.

“I’m stunned,” Ms. Albright told the host of ABC’s “This Week,” George Stephanopoulos. “I’m, frankly, stunned, George, that they have not been involved in it.”

Ms. Albright called on Ms. Rice and other foreign ministers to leave the summit in Russia immediately and fly to the Middle East to calm the fighting.

“There’s no question in my mind that Iraq has diverted everybody’s attention from really looking at a whole host of other issues,” Ms. Albright said. “It has not helped our relationships in the Middle East generally. So I do think that Iraq is turning out to be a huge disaster, and with many, many unintended consequences, one of which is the fact that Iran has gained more and more influence and is in a position to be helpful to the Hezbollah in a way that it was not before.”

Ms. Rice described as “grotesque” claims that administration policies were to blame for the current violence.

Mr. Bush’s said repeatedly yesterday that the “root cause” of the new fighting was the presence of armed militants on Israel’s borders. The president’s language clearly irked Arab diplomats, who often use the same phrase to denounce Israel’s presence on territories claimed by Arabs.

“When I heard President Bush saying we should address the root cause of the problem, I felt happy. I thought, finally, they will address the root cause of the problem, which is the ongoing occupation and humiliation of the Palestinians, the daily infringements on Lebanese sovereignty. And then, once again, he said, ‘It’s Damascus; it’s Tehran,'” the Syrian ambassador to America, Imad Moustapha, told CNN’s “Late Edition.”