Brussels ? NATO allies will bolster the American troop surge in Afghanistan by sending at least 7,000 soldiers of their own, officials said Friday in pledges that U.S. Secretary of State Hillary Rodham Clinton described as crucial to turning the tide in the stalemated war.

The promised increase came as U.S. Marines and Afghan troops launched the first offensive since President Barack Obama announced a 30,000-troop American increase. The Marines and Afghan forces struck Taliban communications and supply lines Friday in an insurgent stronghold in southern Afghanistan.

In yet another war development, U.S. officials said the Obama administration may expand missile strikes on al-Qaida and the Taliban inside Pakistan and will focus on training Pakistan’s forces in a border area where militants have been aiding the Afghan insurgency.

The Marine Corps offensive was part of preparations for the arrival of the 30,000 U.S. reinforcements, Gen. David Petraeus told The Associated Press. The top general in charge of both the Afghanistan and Iraq wars said the military has been working for months to extend what he called “the envelope of security” around key towns in Helmand and Kandahar provinces.

In Brussels, Clinton told allied foreign ministers that it was essential that contributions to the war effort be provided as quickly as possible. She thanked Italy for its announcement that it will send an additional 1,000 troops and Britain for its pledge of another 500, but she said nonmilitary assistance is equally important.

“The need for additional forces is urgent, but their presence will not be indefinite,” she told the North Atlantic Council, NATO’s highest political group.

NATO Secretary-General Anders Fogh Rasmussen of Denmark told reporters at the organization’s headquarters that still further NATO forces might be in the offing, suggesting there would be “more to come.”