Chief U.N. weapons inspector Hans Blix said Wednesday's resumption of inspections in Iraq after nearly four years was "a good start."

But he cautioned that a long, demanding process was just beginning and it's too early to say what the final result will be.

"I think it all went as we had expected," he told a small group of reporters after the first two teams of U.N. experts began their search for any hidden Iraqi nuclear, chemical or biological weapons and long-range missiles to deliver them.

"I wouldn't want to predict too much simply because we have had one day without conflict. I think the Iraqis are in a mood that they would like to be helpful and to have inspections without any friction and that's a good start," Blix said.

He said talks with the Iraqis in Vienna and Baghdad on practical arrangements for the resumption of inspections had paid "some dividends." He cited inspectors flying from Larnaca, Cyprus to Baghdad without problems, a helicopter station being set up by the end of the week at Rashid Airport in the Iraqi capital, and a "hot line" being established between the U.N. inspectors' office and the National Monitoring Directorate, its Iraqi counterpart.

"So there were no particular problems of any kind really at the moment," Blix said. "But of course the results of the inspections are not just that you can go in and out without any conflict. It's also samples that you're taking and so forth. That's more of a long-term thing."

In a televised interview, Blix said the biggest difference between previous inspections and the new inspections is "backing from the Security Council."

The council unanimously adopted a new resolution on Nov. 8 demanding that Iraq's weapons of mass destruction programs be eliminated, tightening the rules for inspections, and threatening "serious consequences" if Saddam Hussein doesn't cooperate.

"The most important thing for us in the new resolution is that the inspectors' demands will be backed up," he said.

"We maintain that the burden of proof is on Iraq," Blix said. "They object and say that anyone who is arraigned before a tribunal is acquitted if the prosecutor cannot prove the case.

"We say you are not in a criminal tribunal; you are in a situation where you want to create confidence that Iraq doesn't have any anthrax or anything else that's prohibited. That takes more than there's no evidence of it," he said.

Blix also said that Iraq had not objected to the Dec. 8 deadline for filing a declaration listing all its military and civilian programs that could be involved in the production of weapons of mass destruction.

"The Iraqis are worried about the extent of it [the declaration], but they didn't raise any point about the date," Blix said.

He said the Iraqis asked if they were required to report every program, "the production of slippers by chemical or whatnot. They didn't ask about the timing."

Asked what he expected by Dec. 8, Blix said: "By Dec. 8 they should account for it all."

But Iraq has a large chemical industry, and he said if the Iraqis tell the United Nations that they are unable to account for everything in the chemical sector, "I don't think it's a big issue actually."