U.N. inspectors got tougher with Iraq in word and deed Wednesday, hunting for banned weapons in President Saddam Hussein's main palace and demanding active help from Iraq so they could get the job done. "I intend...to impress upon Iraq the need to shift gear from passive cooperation to active cooperation," Mohamed ElBaradei, head of the United Nations International Atomic Energy Agency, told reporters after meeting officials in Moscow.

Russia said it would send its own leading Iraq expert to Baghdad, perhaps as early as Wednesday. It hopes to avert any U.S.-led war, fearing in part that military action would imperil Russian government and business interests in Iraq.

In the heart of Baghdad, seven carloads of inspectors drove into the vast al-Jamhoury presidential palace compound. It was the second of Saddam's palaces inspected since U.N. experts resumed their work on November 27 after a four-year break.

The experts were granted immediate access, and one of their cars blocked the main entrance. Saddam's main office is at the palace but it was unclear whether he was there. Some inspectors left after about two hours while others stayed behind.

In Washington, President Bush warned Iraq on Tuesday that his patience was running out for it to come clean over any weapons of mass destruction, as required by a resolution of the United Nations Security Council.

"I'm sick and tired of games and deception," Bush said as a huge build-up of U.S. warplanes, ships and tens of thousands of troops in the oil-rich Gulf region gathered pace. "Time is running out on Saddam Hussein. He must disarm," Bush said.

Iraq, the world's eighth biggest oil exporter under tight U.N. sanctions, but whose proven oil reserves are second only to Saudi Arabia's, said Tuesday it had nothing to hide. "Saddam Hussein is a courageous leader and will...fight until the last Iraqi bullet," Deputy Prime Minister Tareq Aziz said.

TOUGH TALK IN BAGHDAD THIS WEEKEND

ElBaradei has said he and fellow top United Nations inspector Hans Blix are going to Baghdad this weekend for some tough talking on whether Iraq has chemical, biological or nuclear weapons or long-range missiles.

The talks will be key to a major report that Blix and ElBaradei are due to make to the Security Council on January 27 on Iraqi compliance.

"While the international community is ready to give us some more time, I am also aware that there is a certain degree of impatience in the international community," ElBaradei said.

"We are going to intensify our inspection process in the next few weeks and months." He said they were acting also on intelligence received from other countries.

Russia said its deputy foreign minister and leading Iraq expert, Alexander Saltanov, would travel to Baghdad.

"He will present our views and consider possible steps to ensure a political and diplomatic solution to the Iraqi problem," a ministry spokesman said in a statement.

Since resuming inspections, U.N. experts have found no concrete evidence that Iraq possesses or is developing nuclear, chemical or biological arms. But they say it has failed to account for some items in its 1990s arsenal.

Iraq says it has no such weapons, having destroyed anything that would have breached U.N. resolutions before inspectors returned in November.

Washington and London have threatened war to back up their intelligence that Iraq does have arms of mass destruction, and U.S. officials have signaled that any failure by Baghdad to cooperate with the inspectors could trigger military action.

Neither the United States nor Britain has declared a date for war, but one U.S. official said this week there could be no invasion until March.

April in the Gulf heralds fierce summer heat and sandstorms.

Even before any shots are fired, many in the world are questioning what will happen if Bush achieves his long-stated wish to oust Saddam, who has wielded power for three decades.

Iraq, a country of some 24 million, has long posed problems for rulers due to ethnic and religious divides. Shi'ite Muslims form a majority over Sunnis like Saddam, who have traditionally ruled the country, and there is a sizeable Kurdish minority.

U.S. officials have said their aim would be to disarm Iraq, preserve its current borders and set up a democratic government representative of Iraq's ethnic and religious communities.

PHOTO CAPTION

An Iraqi soldier stands in front of the U.N. weapons inspectors' vehicles, waiting to enter the Al-Jamhoury Presidential Palace in central Baghdad on January 15, 2003. U.N. inspectors got tougher with Iraq in word and deed, hunting for banned weapons in Hussein's main palace and demanding active help from Iraq so they could get the job done. (Faleh Kheiber/Reuter