Saudi Arabia's anti-terrorism cooperation with the United States has increased sharply since a terrorist attack in Riyadh (search) in May that killed 34 people, a senior administration official said Thursday.

As an example, the official said the two countries set up a joint counterterrorism operations center after the May 12 incident. He added that the Saudis were much more inclined than before to share information with U.S. law enforcement officials.

In addition, he said, no other country has killed more Al Qaeda (search) militants over the past five months than Saudi Arabia.

The official, a top administration expert on Saudi issues, spoke to a group of reporters on the condition that he not be identified by name or position.

Both Saudi and U.S. officials have linked Al Qaeda to the May bombing, which targeted three residential compounds in Riyadh.

Other administration officials also have praised the more assertive Saudi posture on terrorism in recent months.

Assistant Secretary of State William Burns said in a speech three weeks ago that Crown Prince Abdullah of Saudi Arabia "has acted decisively to strengthen counter-terrorism cooperation," especially since the May attacks.

The Bush administration generally defended Saudi counterterrorism cooperation in the war on terror after the Sept. 11 suicide bombings while acknowledging that more needed to be done.

Privately, some officials expressed criticism of the Saudis, leading to numerous media accounts that highlighted supposed Saudi shortcomings.

The kingdom came under increased scrutiny following the disclosure that 15 of 19 suicide bombers involved in the Sept. 11 attacks were Saudi nationals, as is Usama bin Laden (search).

Reports surfaced this summer about possible links between Saudi intelligence officials and the Sept. 11 hijackers. In addition, U.S. officials said some militants who have been attacking U.S. soldiers in Iraq came from Saudi Arabia.

The senior official said Thursday that only a handful of Saudis had crossed the border into Iraq on such a mission.

He added that Saudi Arabia assisted the U.S. military during the Iraq war this past spring in ways that never have been discussed publicly.

The official cited this kind of cooperation to point out that, for the United States, Saudi Arabia is important for more than its oil.

Prince Bandar, the longtime Saudi ambassador to Washington, said Thursday that the U.S. military presence should remain in Iraq for now. However, he said, Saudi Arabia has no plans to provide any peacekeeping troops and the country's neighbors should follow its lead by staying out of the military aspect.

"We don't want to politicize the stability of Iraq," he told students at Tufts University near Boston.

The senior administration official suggested that however tempting it may be for outsiders to criticize the absence of democracy in Saudi Arabia, the alternative could be a Taliban-type regime.

The official said the United States needs moderate voices in the Middle East, such as the Saudis, to help promote a settlement between Israel and the Palestinians.

He credited the Saudi royal family with trying hard to move the nation culturally into more modern times, often in the face of fierce resistance.