The U.S.-led coalition must "get on top of the security situation" in the critical months leading to Iraqi self-rule, British Prime Minister Tony Blair said during a surprise visit here.

On Monday, a top official in Blair's government said that British troops would likely remain in Iraq for years to come.

Blair said Sunday that the conflict in Iraq was a test case in the global fight against terrorism and repression, and one that serves as a warning to other "rogue repressive states developing weapons of mass destruction."

In London, Foreign Secretary Jack Straw said Monday that British forces would likely remain in the country for years to come.

He said he could not give an "exact timescale" for their withdrawal but added that "it is not going to be months. ... I can't say whether it is going to be 2006, 2007."

Britain has some 10,000 troops stationed in and around Basra in southern Iraq.

Blair's top envoy in Iraq, Sir Jeremy Greenstock, warned Sunday that insurgents likely will stage bigger and more sophisticated attacks.

"The opposition is getting more sophisticated, using bigger bombs and more sophisticated controls. We will go on seeing bigger bangs," Greenstock told reporters after meeting with Blair.

Blair said: "The important thing is to realize we are about to enter into a very critical six months. We have got to get on top of the security situation properly and we have got to manage the transition. Both of those things are going to be difficult."

On New Year's Eve, a car bomb killed eight people celebrating in an upscale restaurant in Baghdad, the capital. On Dec. 27, coordinated strikes including four car bombs struck the southern city of Karbala, killing 19 people, including seven coalition troops, and wounding some 170.

Coalition reports of attacks around the country Sunday were fairly routine: two mortar shells exploded near the coalition headquarters in the southern city of Nasiriyah, causing no damage or injuries; insurgents ambushed a U.S. foot patrol in northern Tikrit, injuring one American soldier; and a homemade bomb exploded as a U.S. convoy was passing in Beiji, wounding three U.S. soldiers.

Witnesses reported that gunmen wounded coalition-appointed lawyer Mohammed al-Jawadi and his son in a failed assassination attempt in the northern city of Mosul on Monday morning. Sources at the local hospital said al-Jawadi, the general prosecutor of a newly established court to fight corruption, was in critical condition but his son's life was not in danger.

Greenstock said he thought 75-80 percent of attacks were being carried out by loyalists of ousted Iraqi leader Saddam Hussein and the rest by foreign terrorist groups that were putting in place "cell structure."

Blair, a staunch ally of the United States whose popularity plummeted amid allegations his government overstated the threat from Saddam Hussein, used his visit Sunday to reiterate charges that preceded the U.S.-led invasion.

Saddam's Iraq, he said, embodied the dual threats facing the world from the "incredibly dangerous" terrorism that is "a perversion of the true faith of Islam" and brutal and repressive regimes that use weapons of mass destruction.

Those threats produce "chaos" and "the whole world system, economically and politically, breaks down," he said.

Later, in a briefing on a plane, he indicated to reporters that the Iraq invasion serves as a warning to other countries developing weapons of mass destruction. "It's important to say to countries that may have engaged in such programs: 'Look, there's a different way of dealing with this,'" Blair said.

Since the invasion, Libya and Iran have allowed initial visits by U.N. inspectors and there are hopes it could curb and influence other countries.

Blair said Saddam had a "proven record of use of weapons of mass destruction."

"Brutal and repressive states that don't actually have the support or consent of their people that are developing weapons which can cause destruction on a massive scale are a huge, huge liability to the whole security of the world," Blair said.

"This conflict here was a conflict of enormous importance because Iraq was a test case," Blair told some of the 10,000 British troops stationed in and around Basra, 340 miles southeast of Baghdad. "If we backed away from that, we would never be able to confront this threat in the other countries where it exists."