KABUL, Afghanistan - Democratic presidential contender Barack Obama started a campaign-season tour of combat zones and foreign capitals, visiting with U.S. forces in Kuwait and then Afghanistan — the scene of a war he says deserves more attention and more troops.

The Illinois senator arrived Saturday in Kabul as part of an official congressional delegation and then flew to eastern Afghanistan. Staff. Sgt. David Hopkins said Obama and two other senators were making a brief stop in Jalalabad airfield, in Nangarhar province, to visit with soldiers stationed there.

Obama's first visit to Afghanistan, coming less than four months before the general election, was rich with political implications. Republican presidential rival John McCain has criticized Obama for his lack of time in the region. Obama is also expected to stop later in Iraq.

Robert Gibbs, a campaign spokesman, said Obama arrived in Kabul around noon. En route from Washington, he made a stopover in Kuwait to meet with U.S. forces stationed there, Gibbs said.

Sultan Ahmad Baheen, spokesman for Afghanistan's Foreign Ministry, confirmed the senator was in Afghanistan and that he would meet with President Hamid Karzai.

"I look forward to seeing what the situation on the ground is," Obama told a pair of reporters who accompanied him to his departure from Andrews Air Force Base on Thursday. "I want to, obviously, talk to the commanders and get a sense both in Afghanistan and in Baghdad of, you know, what the most, their biggest concerns are, and I want to thank our troops for the heroic work that they've been doing."

Underscoring the challenges in Afghanistan, authorities reported Saturday that a roadside bomb killed four policemen in the volatile south of the country where the Taliban-led insurgency is intensifying nearly seven years after a U.S.-led invasion ousted the militant movement from power.

Troop shift urged
Obama advocates ending the U.S. combat role in Iraq by withdrawing troops at the rate of one to two combat brigades a month. But he supports increasing the military commitment to Afghanistan, where the Taliban has been resurgent and Osama bin laden is believed to be hiding.

Obama recently chided Karzai and his government, saying it had "not gotten out of the bunker" and helped to organize the country or its political and security institutions.

Also on his itinerary later in the trip is a meeting with Nouri al-Maliki, the Iraqi leader. On the campaign trail, Obama has said one benefit of withdrawing U.S. troops is that it would pressure al-Maliki to shore up his government as well.

Nonetheless, he said he did not plan to reiterate those messages in person.

"I'm more interested in listening than doing a lot of talking, and I think it's very important to recognize that I'm going over there as a U.S. senator," he said. "We have one president at a time."

The duration and details of Obama's stay in Afghanistan have not been formally disclosed, and media access was limited.

Traveling with Obama were Sens. Chuck Hagel, a Nebraska Republican and Jack Reed, a Democrat from Rhode Island. The senators, both military veterans, have been mentioned as potential Obama vice presidential running mates, but Reed has said he's not interested in the job.

In a speech this week, Obama said the war in Iraq was a distraction, unlike the fighting in Afghanistan.

"This is a war that we have to win," he said. "I will send at least two additional combat brigades to Afghanistan, and use this commitment to seek greater contributions — with fewer restrictions — from NATO allies.

"I will focus on training Afghan security forces and supporting an Afghan judiciary, with more resources and incentives for American officers who perform these missions."