Chief U.N. inspector Hans Blix said Wednesday he will tell Iraq the situation is "very dangerous" but it can still prevent war by providing new evidence about its nuclear, chemical and biological weapons programs.

Blix and Mohamed ElBaradei, head of the International Atomic Energy Agency, will deliver the message during their visit to Iraq on Sunday and Monday. The visit comes ahead of their Jan. 27 report to the U.N. Security Council on Iraq's cooperation with U.N. inspections, which resumed in late November after four years.

"The message is that they are in a tense situation and we would want them to cooperate more on the substance and provide more evidence in particular," Blix said as he left U.N. headquarters for Brussels, Paris and London en route to Baghdad.

"They have provided prompt access, been very cooperative in terms of logistics," Blix said. "But they need to do a good deal more to provide evidence if we are to avoid any worse development."

Asked whether the Baghdad trip was a last chance for the Iraqis, Blix said: "There's still time, I think, for Iraqis to get themselves out of a very dangerous situation."

President Bush expressed impatience with Saddam Hussein on Tuesday and said "time is running out for him" to disarm. But White House spokesman Ari Fleischer said Wednesday that Bush "has made no decisions about whether or not we will go to war."

"Indeed, much of it still depends on Saddam Hussein and whether Saddam Hussein will get the message that time is running out and he needs to actively comply with the inspections and the inspectors," Fleischer said.

ElBaradei's spokesman, Mark Gwozdecky, said Sunday that U.N. teams would need about a year to carry out "credible" inspections of Iraq's nuclear program. Blix has said his teams need months.

"If we get the evidence from the Iraqis, then you don't need much time at all," Blix said Wednesday. "But if it takes a lot of time to do that, then it's worse."

Blix and ElBaradei told the Security Council last week that inspectors had found no "smoking guns," but they said Iraq's 12,000-page declaration was very short on new evidence to verify Baghdad's claims that its nuclear, chemical, biological and long-range missile programs have been destroyed.

Blix said that during a meeting with U.S. national security adviser Condoleezza Rice on Tuesday, Rice focused on the importance of the Jan. 27 report to the Security Council and Iraqi cooperation.

"She wants us to examine the declaration again," Blix said. "We have given some examples of things that we don't think it covered and I think she would like us to give an assessment of the cooperation both from the ground in terms of inspection, and in terms of how we see the report now that we have analyzed it even further."

Resolution 1441, which was adopted unanimously on Nov. 8, the Security Council gave Iraq a final opportunity to disarm and threatened serious consequences if it didn't. It says says false statements or omissions in Iraq's declaration and a failure to cooperate in implementing the resolution would constitute a new "material breach" that would be reported to the council for discussion and possible action.

Russian Foreign Minister Igor Ivanov was quoted by the Interfax news agency on Wednesday as saying war without Security Council approval "is capable only of worsening the already difficult situation in the region and would lead to unpredictable consequences for international peace and stability."

Canadian Prime Minister Jean Chretien said Wednesday he also wants U.N. backing for any military campaign against Iraq, but he refused to rule out Canada's participation in a U.S.-led strike without Security Council approval.

Council diplomats said Rice raised two other key issues with Blix. The United States wants Iraqi scientists interviewed outside the country in the immediate future. And it wants inspectors to delay formally listing the tasks that Iraq must complete to have sanctions suspended until Baghdad fills in the gaps about its weapons programs.

Blix said he told the council last week that he plans to start work on the list of Iraq's key remaining disarmament tasks after Jan. 27 and submit it to the council at the end of March. He noted that this is called for in the council resolution adopted in December 1999 establishing the U.N. Monitoring, Verification and Inspection Commission, which he heads.

U.S. Ambassador John Negroponte raised the issue of delaying preparation of the list at a Security Council luncheon on Tuesday with Secretary-General Kofi Annan which Blix also attended. Diplomats said France and Russia opposed a postponement.

At the U.S. request, the Security Council will take up the issue Thursday.