BAGHDAD, Iraq (CNN) -- Iraqi Deputy Prime Minister Tariq Aziz says accusations by U.N. weapons inspectors that his country put deadly VX nerve gas on missile warheads are a "political trick" designed to maintain economic sanctions against Iraq.

In Baghdad, the Iraqi government insisted that U.S. Army laboratory tests showing traces of VX on fragments of destroyed warheads were "baseless and mere fabrications."

VX is a colorless, odorless liquid that turns into a gas when it comes into contact with oxygen. A few drops can kill in minutes.

In a statement issued Wednesday, over the signature of President Saddam Hussein, Iraq also warned that it would reconsider its relations with U.N. inspectors if sanctions were not lifted. The statement warned of "grave consequences" but did not elaborate.

"When other means to lift the sanctions fail due to the hostility and evil of some parties, there will be no alternative to the strategy ... to get rid of the unfair embargo," the statement said.

VXTREME CNN's Bernard Shaw interviews chief U.N. weapons inspector Richard Butler VXtreme streaming video (3:25)

While admitting that Iraq once manufactured VX nerve gas, the Baghdad regime always has maintained that it never loaded the gas into missile warheads or any other weapons system.

But on Wednesday, U.N. chief weapons inspector Richard Butler told members of the Security Council that "unambiguous" evidence of VX was found during an analysis of fragments of warheads at the Army laboratory at Aberdeen, Maryland.

"I explained to the council that [the findings are] very serious because Iraq has always insisted that it never weaponized VX," Butler said. "These findings show that they did weaponize it. They put it in missile warheads."

Asked if the findings could have been in error, Butler said no, adding that the results leave "no doubt" that Iraq put VX on warheads. However, he said the fragments will be sent to laboratories in France and Switzerland for additional testing to satisfy Iraqi demands. ( 245K/20 sec. AIFF or WAV sound)

The disclosure of the lab's analysis came as the Security Council was to debate whether to continue the sanctions on Iraq -- timing that Aziz found suspicious.

"To say this now, and to say it in this way, is a political trick," said Aziz, who is on a trip to Spain.

If the findings are confirmed, they could undermine efforts by three of the five permanent members of the Security Council -- Russia, France and China -- to end the seven-year inspection program and lift crippling economic sanctions imposed in 1990 after Iraq invaded Kuwait. The invasion led to the Persian Gulf War.

It was unclear whether the new evidence would be enough to persuade the Russians, French and Chinese to change their position.

French Ambassador Alain Dejammet, one of the strongest critics of the inspection program within the 15-member council, said if the European laboratories uphold the findings, "it would be a matter to be discussed very seriously."

In an interview with CNN, Butler indicated that the discoveries about VX, while serious, would not necessarily lead to an extension of sanctions. But he said the episode shows that Iraq needs to be more forthcoming in providing information about its past weapons programs.

"We've said to them, 'This is a very surprising and somewhat shocking finding. We don't want to accuse you beyond saying, look, this is what we've found here. Help us. Tell us the truth. How much of this stuff did you make and how much of it did you weaponize?'" Butler said.

Asked for his reaction to Iraq's statement about "grave consequences" for weapons inspectors, Butler said, "I'm not sure why they're talking like this." ( 391K/34 sec. AIFF or WAV sound)

A U.S. Army laboratory says it has detected traces of VX nerve gas on Iraqi missile warheads

Iraq's toughest critics among the Security Council's permanent members -- Britain and the United States -- said the findings about VX underscore the need for Baghdad to disclose all information on its weapons programs if it expects an end to sanctions.

The U.S. ambassador to the United Nations, Bill Richardson, accused Iraq of "deceiving the international community." ( 255K/23 sec. AIFF or WAV sound)

"I think Iraq is conducting its diversion and deception campaign, and it's not working," Richardson said. "Facts are facts." ( 221K/20 sec. AIFF or WAV sound)

The British ambassador, John Weston, called the VX findings "obviously a very serious matter."

"The truth is not relative, the truth is not what you can get away with," Weston said. "It is not a case that the rest of the world is out of step with them."

U.N. Secretary-General Kofi Annan, who in February brokered a deal with the Iraqis to resume weapons inspections and avert U.S.-led airstrikes, said he hoped the findings would not hinder the improved working relationship between Baghdad and the United Nations.

"We are dealing with the Iraqis on a large spectrum of issues, and I hope this particular development will not destroy the improved relations that has allowed [weapons inspectors] to carry on," he said.

Reuters contributed to this report.

Interactive Features ---------- Primer: Bioweapons Who's who Inside UNSCOM Gulf War recap Military databanks Interactive Maps ---------- UNSCOM search sites Iraq's arsenal Key Iraq locations Allied forces

CNN/Time Impact: Inside UNSCOM: The Inspectors' Story Related stories: Iraq, U.N. reach agreement on disarmament plan - June 14, 1998 Iraq resisting British conference on aid shipments - April 11, 1998 U.N.'s Butler returns to Baghdad - March 22, 1998 Baghdad calls for better relations with U.S. - March 15, 1998

Latest Headlines Pakistan begins troop withdrawal from Indian border White-collar workers in Jakarta join anti-Habibie chorus Veteran politicians hand over EU reform blueprint Klan rally in New York fizzles under counterprotests Falwell hosts summit with gay minister Critics assail plan to give women addicts money to use birth control Chemical that could power microbes is found at Jupiter moon Texas downs No. 3 Huskers, continues hex Illinois stuns No. 9 Michigan 35-29 Agilent plans $1.1 B IPO Agents boycott United for slashing commissions Advocates assail legislation encouraging mergers Today on CNN

Related sites: Note: Pages will open in a new browser window Iraqnet United Nations United Nations Special Commission (UNSCOM) External sites are not endorsed by CNN Interactive.