Iraq said it destroyed six more banned Al Samoud-2 missiles today, but a senior adviser to President Saddam Hussein warned that it would stop doing so if the United States pursues plans to invade Iraq without obtaining approval from the U.N. Security Council.

"If it turns out, during an early stage this month, America is not going the legal way, then why should we continue?" Gen. Amir Saadi, Hussein's top science adviser, said at a news conference.

The destruction of the missiles had been portrayed as a crucial test of whether Iraq would abide by the terms of U.N. Resolution 1441, which requires Baghdad to account for its weapons of mass destruction. Last week, Iraq announced it would destroy the missiles, and that announcement appeared to provide support to the positions of France, Germany and other countries on the Security Council that oppose military action by the United States and are asking for the inspections to be extended.

The United States, however, argued last week that enough time had elapsed and that Iraq remained in material breach of the U.N. resolution.

A senior U.S. official said today that the White House remained unimpressed with Iraq's moves. "The standard for cooperation demanded by U.N. Resolution 1441 is full and immediate, not grudging and late," the official said. The resolution, approved last fall, authorized a new round of weapons inspections in Iraq.

Iraq destroyed the missiles as leaders of Turkey's ruling party said no decision had been made on whether to seek a second vote in parliament on whether to allow Turkish bases to be used in any U.S. military action. The parliament on Saturday rejected a request for the deployment.

In Iraq, the inspectors are trying to ensure that a stockpile of several dozen fully operational missiles, equipped with warheads and guidance systems, are among the first to be taken out of commission. Four Al Samoud-2s were flattened by bulldozers on Saturday, and Saadi said technicians bulldozed six more missiles in the presence of U.N. arms inspectors today. He said Iraq would seek to maintain that pace over the next few days.

Saadi said Iraq has about 100 operational Al Samoud-2s and as many as 20 others in various stages of assembly. If Iraq maintains the current rate of destruction, it could take almost three weeks to finish the task.

The chief U.N. weapons inspector, Hans Blix, ordered Iraq to destroy all of its Al Samoud-2s and related components after a panel of international experts concluded, based on data provided by the Iraqi government, that the missiles are capable of traveling beyond a 93-mile limited imposed by the Security Council after the 1991 Persian Gulf War. Iraq objected to the decision but opted to comply in an apparent effort to forestall a U.S.-sponsored council resolution that would deem Iraq in breach of its disarmament obligations and effectively provide U.N. endorsement for a U.S.-led war to topple Hussein's government.

Although the Al Samoud-2s are among Iraq's newest weapons systems, Western military analysts question the missiles' accuracy. At this evening's news conference, Saadi said they would not be instrumental in Iraq's efforts to fend off a U.S. invasion.

"These weapons are quite useful," he said. "However, they're not decisive in the battlefield, so sacrificing them is something that has been calculated by us" as acceptable.

Saadi argued that Iraq's decision over the past few days to start destroying the banned missiles, offering scientists for private interviews and excavating sites for evidence of its past weapons programs should be considered "proactive cooperation" with the inspectors -- a phrase Blix has used frequently to describe what he wants from Hussein.

"To all fair-minded people who are neutral and free, it's more than enough," Saadi said. But he acknowledged that Iraq's efforts probably would not be sufficient to guarantee the rejection of the U.S.-sponsored resolution.

"There are all kinds of pressures, unbearable pressures sometimes, and that in and of itself is an indication" of what might occur, he said.

Saadi also urged Americans to reevaluate their support for a war in Iraq, noting that military action could cost the United States at least $80 billion. He said the U.S. government, which claims to have geographic coordinates of facilities allegedly engaged in the production of banned weapons, should instead give that information to the inspectors.

"It would be much easier and less costly and much faster to provide those coordinates" to the U.N. inspection commission, he said. "They'll do the job free of charge, at no cost to the American taxpayer."

Even though Iraq has sought to cast its behavior over the past several days as cooperative, U.N. officials said they are withholding judgment, perhaps until they must compile a presentation that Blix will deliver to the Security Council on Friday.

U.N. officials have expressed guarded optimism about the decision of a few non-nuclear scientists -- two on Friday and one on Saturday -- to consent to private interviews with inspectors. Two other scientists whom the inspectors had sought to interview on Saturday refused to be interviewed without a witness or a tape recorder, while a fourth could not be located. Another scientist refused a private interview today, according to Iraq's Foreign Ministry.

U.N. officials also are skeptical of Iraq's attempt to prove it destroyed 157 aerial bombs filled with biological warfare agents by excavating an abandoned helicopter airfield about 60 miles southwest of Baghdad where Iraq claims the destruction occurred. Saadi said technicians have found numerous bomb fragments and eight intact R-400 bombs, which were probably filled with anthrax bacteria, aflatoxin or botulinum toxin.

But inspectors said they doubt that debris and soil tests will be able to determine the volume of weapons destroyed at the site, as Iraq contends. The inspectors nonetheless took samples of the material in the bombs today to confirm its composition.

Saadi said Iraq does not want photographs or videotape of the destruction of the missiles to be released, despite the potential impact on world opinion, because the impact on the people of Iraq would be "too harsh."

Iraqi newspapers and television stations, all of which are controlled by the government, did not report on the destruction. Instead, Iraqis saw Hussein on the television news tonight, listening to army officers informing him of their readiness for war. One officer told Hussein that U.S. planes have been dropping leaflets urging Iraqi soldiers to surrender.

"They weren't able to defeat us with bombs," Hussein said. "Are they going to defeat us with leaflets?"

Staff writer Dana Milbank in Washington contributed to this report.

Gen. Amir Saadi, an adviser to Hussein, said the banned Al Samoud-2 missiles are "quite useful" but not decisive in battle, so "sacrificing them" is acceptable to Iraq.