WASHINGTON — President Bush has ordered helicopters and ships to Lebanon to provide humanitarian aid, but he still opposes an immediate cease-fire that could give relief from a 13-day-old Israeli bombing campaign.

Announcing the assistance program, White House press secretary Tony Snow said Monday there was no reason to believe an immediate cease-fire would stop violence in the Mideast and said instead the world should confront the destabilizing force of Hezbollah and its practice of using the Lebanese people as "human shields."

Israel's bombardment has demolished Lebanon's infrastructure and killed hundreds. It began after Hezbollah captured two Israeli soldiers.

"At the order of the president, humanitarian supplies will start arriving in Lebanon tomorrow by helicopter and by ship," Snow announced at the White House. "We are working with Israel and Lebanon to open up humanitarian corridors."

Snow said that Secretary of State Condoleezza Rice discussed the assistance with officials during a surprise visit to Beirut Monday and would talk about further about the U.S. commitment later in the day as she continued on to Israel. Snow did not give any more details about what the United States would send, other than to describe it as "a significant U.S. commitment."

At the Pentagon, spokesman Bryan Whitman said the assistance will include tons of medical equipment and other supplies that will be delivered from Cyprus to Beirut. He said the U.S. military is nearing completion of the evacuation of American citizens and can switch its focus to the humanitarian mission.

The announcement came a day after officials from U.S. ally Saudi Arabia came to the White House to personally request that Bush help press for an immediate end to the violence between Israel and Hezbollah in Lebanon. But Snow said that could be a "fool's errand."

"Look, we would like a cease-fire tomorrow," he said. "We would like a cease-fire immediately. But it has to be a cease-fire that is going to stand the test of time so the people in that region and people in Lebanon particular, a country that has been hard hit by occupying forces and by frustrations of its democratic aspirations, deserve a shot at having the freedom and democracy its people deserve. And the only way that's going to be possible is if there is no longer an internal threat of the sort that we've witnessed in recent weeks."

Snow said the humanitarian aid is not designed to mute criticism of the U.S. in the region but is strictly to aide innocent people who are being hurt.

Asked why the aid has taken two weeks to deliver, Snow said, "The fact is, that we're first to the scene." And he said the U.S. was calling on other allies to send help as well.

Whitman said it is likely that some of the faster moving ships, such as the Italian fast ferry Vittoria M. and the Navy's high speed catamaran HSV-2 Swift, will be used to carry the supplies to aid agencies operating in Lebanon. He said it is not likely that the military will be transporting the supplies, including blankets and large medical kits, over land to other locations in the country.

Nearly 12,000 Americans have been evacuated over the past week, including more than 2,000 in the past 24 hours, said Whitman.

Snow said the U.S. has been discussing the aide with Israel to make sure the supplies will get to Lebanon safely. But he no one in the United States has discussed specific targets with the Israelis.

In an Oval Office meeting Sunday, Saudi officials gave Bush a letter from Saudi King Abdullah, asking that the U.S. president intervene in Israel's military campaign to stop the bloodshed.

For years, the Saudis have been among the United States' closest allies in the Arab world, despite strains from U.S. pressures aimed at increasing democracy in the conservative kingdom. Reflecting their influence, Bush cut another night off a weekend stay at his Texas ranch where he spent time fishing and biking to attend the meeting with Rice and the Saudis.

"The U.S. has the authority, it has the clout with Israel," said Nail al-Jubeir, a Saudi Embassy spokesman. "For us to go and talk to the Israelis isn't going to do anything."