Defense Secretary Donald H. Rumsfeld (searchlauded the work of Iraqis who are stepping forward to help keep peace in their own country during a visit Monday with American occupation officials and members of Iraq's new security services.

Details of Rumsfeld's visit to Iraq were closely held in advance for security reasons.

He arrived Monday morning from Kuwait and helicoptered to the headquarters of the 10th Armored Calvary Regiment east of Baghdad (search).

It was his fourth trip to the region since the U.S.-led coalition ousted Saddam Hussein (searchfrom last spring.

Rumsfeld met with four young members of Iraq's new security forces and told them he was impressed with the progress they were making.

"We're looking forward to seeing Iraqis take over the responsibility for the security of your country," he told them.

At the 10th Armored headquarters, U.S. officers briefed Rumsfeld on continuing efforts to turn more and more to Iraqi police and civilian defense agencies as the primary providers of security in Iraq, while decreasing the visible American presence.

The U.S. officers told Rumsfeld that the chief threat to Iraq's stability is moving away from former members of Saddam's regime and toward international terrorist organizations such as Al Qaeda.

An estimated 200,000 Iraqis have joined the various Iraqi security services in the last several months despite strong attacks that have killed more than 300 Iraqis in recent weeks.

The latest attack was Monday in Kirkuk and occurred at roughly the same time Rumsfeld was visiting Baghdad, hundreds of miles to the south. A vehicle bomb detonated outside a police station in a Kurdish neighborhood of the ethnically divided northern city, killing at least four people and wounding at least 32 others, police and hospital officials said.

Earlier in Kuwait, Rumsfeld met briefly with the prime minister, Sheik Sabah Al Ahmed Al Sabah.

Rumsfeld's tour also will take him to Tashkent, Uzbekistan, his third visit in two years in the Uzbek capital. The Uzbek Foreign Ministry said Saturday he also plans visits to neighboring Kazakhstan and Afghanistan.