As Prime Minister Ariel Sharon arrives today for a White House visit, Israeli officials are redoubling efforts to warn the Bush administration that Iran poses a greater threat than the Iraqi regime of Saddam Hussein.

A series of Israeli leaders have carried that message to Washington recently in the hope of influencing a debate that has centered not on Iran but on whether to pursue the overthrow of the Iraqi government. Sharon's visit, however, comes a week after President Bush focused attention on Iran by including it in his State of the Union address as a member of an "axis of evil" with Iraq and North Korea. During meetings here yesterday, including with Vice President Cheney, Israeli Defense Minister Binyamin Ben-Eliezer warned of the hazards posed by Iranian support for terrorist groups and development of advanced weapons.

"Today, everybody is busy with Iraq," Ben-Eliezer said in an interview. "Iraq is a problem. . . . But you should understand, if you ask me, today Iran is more dangerous than Iraq."

He pointed to Iran's role in the scheme to smuggle 50 tons of weapons into Palestinian hands. American and Israeli intelligence officials have concluded Iran provided the weapons and worked with the Lebanese militant group Hezbollah to transport them by sea to Palestine Liberation Organization Chairman Yasser Arafat's administration. The ship was intercepted by Israeli commandos in the Red Sea a month ago.

Ben-Eliezer stressed his concerns about Iran's pursuit of missiles capable of striking Israel with chemical and biological weapons. He said Iran is on schedule to develop a nuclear bomb by 2005.

When Sharon meets with Bush and other U.S. officials today, he plans to sound the alarm about Tehran's ambitions in Lebanon, according to Israeli officials. Israel has accused Iran of dispatching Iranian Revolutionary Guards to foment anti-Israel activity in Lebanon and of providing thousands of missiles to Hezbollah. Iranian and Lebanese leaders had denied these charges.

Though Israeli officials have few kind words for Saddam Hussein, they see him posing less of a threat than Iran after more than a decade of U.N. sanctions and international isolation. But these officials are apprehensive about the price they might pay if the United States seeks to overthrow Hussein and he retaliates by striking Israel.

"I think we are going to be one of the first targets," Ben-Eliezer said.

He said Israeli officials were raising these concerns with Defense Secretary Donald H. Rumsfeld and others in the administration, discussing what steps could be taken to ensure Israeli security in case of a U.S. military thrust against Iraq. Some Middle East analysts have said the United States might have to dispatch troops to western Iraq to hunt down scud missiles, like those Baghdad fired at Israel during the 1991 Gulf War.

"Definitely we are here to exchange some views about what we are expecting, or thinking about how they can defend, or some move that can guarantee the effect will be minimal," Ben-Eliezer said. He said these measures include coordination with the United States concerning troop deployments and anti-missile systems.

Testifying before a House committee yesterday, Secretary of State Colin L. Powell had tough words for Iraq, saying the Bush administration continues to support Hussein's ouster regardless of whether the Iraqi leader allows U.N. weapons inspectors to return. Baghdad offered this week to start talking to the United Nations "without preconditions" about deadlock over weapons inspectors, who have been barred by Iraq for three years.

"Notwithstanding how that unfolds, we still have a U.S. policy of regime change because we believe Saddam Hussein should move on and that the Iraqi people deserve better leadership," Powell said. He said the task of overthrowing Hussein "is something the United States . . . might have to do alone."

Powell's comments about Iran were less foreboding and left open the possibility of dialogue.

"We're making it clear to the Iranians that you've got to choose," he said. "If you want to be part of a world that's moving forward, it's time to stop being a state sponsor of terrorism, get out of the 'axis of evil' column."