Washington will send more troops to Afghanistan "if it's necessary," U.S. Senator John McCain said Saturday using measured words, as he urged increased training for Afghan security forces and the movement of European troops to the country's insurgency-plagued south.

McCain made a strong call on Thursday in Baghdad for 15,000 to 30,000 more U.S. troops in Iraq. But the Arizona Republican on Saturday gave a much feebler — and almost hesitant — endorsement for increased military support for Afghanistan.

Asked if the U.S. would send more troops to Afghanistan, McCain responded, "The British have said that they will be sending additional troops, taking troops out of Iraq and into Afghanistan.

"If it's necessary, we will, and I'm sure we would be agreeable, but the focus here is more on training the Afghan National Army and the police, as opposed to the increased U.S. troop presence."

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A U.N. Security Council mission to Afghanistan has called for additional support in the country, while a report from the Iraq Study Group said that the U.S. should provide "additional political, economic and military support for Afghanistan."

Praising Afghan, U.S., Canadian, British and Dutch forces for bearing "a great deal of the combat responsibilities in recent months," McCain criticized other European allies for not sending their troops where they are more urgently needed.

Other NATO countries with troops in Afghanistan should remove their "national caveats," which make it "extremely difficult for our NATO commanders to call on them for assistance when needed in combat zones, particularly in the southern part of the country," McCain, a 2008 presidential hopeful, said at the U.S. base Camp Eggers in Kabul during a two-day visit in Afghanistan with three other U.S. Congress members.

France, Germany, Italy and Spain said last month at the NATO summit that they would not send troops to fight regularly on the front lines of battles with the resurgent Taliban in the restive south and east.

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"Taliban remains a very big threat, and we have a long way go to before they are eradicated," McCain said of the militia that once ruled Afghanistan, and has re-emerged to fight U.S. and other forces supporting President Hamid Karzai.

In the latest violence, a roadside blast killed one NATO soldier and wounded two others Friday in eastern Laghman province, said a statement from the alliance. The explosion occurred while the troops were conducting an operation.

McCain joined others in criticizing a controversial peace pact between Pakistan's government and Islamic militants in that country's North Waziristan province, bordering Afghanistan.

The International Crisis Group think tank said the agreement has created a virtual Taliban mini-state where mullahs dispense justice and fighters launch cross-border attacks into Afghanistan.

"We don't like it. The attacks from that area have increased, and we think that unless there is some dramatic change, that we will continue to see those increases," McCain said.

Afghan and Western officials have complained that Pakistan does not do enough to prevent terrorists from training on its soil and then crossing the border to attack in Afghanistan. Pakistan says it is standing up to the problem.

McCain said the two countries should stop bickering: "They are fighting a common enemy alongside NATO and the United States. The level of rhetoric needs to be lowered and the level of cooperation needs to be dramatically increased."

Illinois Republican Representative Mark Kirk, a member of a U.S. House committee that approves foreign assistance funding, noted that while there was much debate over how to proceed in Iraq, there was no question about continuing support for the Afghan government.

"I think Congress will be increasing its assistance to Afghanistan," Kirk said.

McCain pressed for more funding from Europe, particularly for counter-narcotics, and warned that Afghanistan could become "Europe's Colombia."

In addition to Kirk and McCain, the delegation visiting Afghanistan also included Republican senators Susan Collins of Maine and John Thune of South Dakota.

The delegation arrived Friday and was scheduled to visits sites of provincial reconstruction and a training area for the Afghan National Army. They were to continue to Pakistan later Saturday.

Click here to go to FOXNews.com's Afghanistan Center.