The highest-ranking U.S. general to lead troops in Afghanistan took command of 35,500 strong NATO-led force Sunday, putting an American face on the international mission after nine months of British command.

Gen. Dan McNeill replaced British Gen. David Richards at the helm of NATO's International Security Assistance Force at a time of increased violence and just before an expected uptick in fighting as spring settles in.

McNeill, who served as coalition forces commander in Afghanistan in 2002-03, told several hundred people gathered for a change-of-command ceremony that ISAF's mission was to facilitate Afghanistan's reconstruction so the "Afghan people might enjoy self-determination, education, health and the peaceful realization of their hopes and dreams."

• More coverage of the struggle for stability is available in FOXNews.com's Afghanistan Center.

"We will quit neither post nor mission until the job is done or we are properly relieved," McNeill said.

The appointment of McNeill, one of only 11 four-star generals in the U.S. Army, raises the profile of the American mission here two weeks after the U.S. Department of Defense extended the tour of 3,200 10th Mountain Division soldiers.

There are now 26,000 U.S. troops in Afghanistan, the highest number since U.S.-led troops ousted the Taliban in 2001 for hosting Osama bin Laden. About 14,000 American forces fall under NATO command; 12,000 troops focused on training Afghan forces and special operations fall under the U.S.-led coalition.

During his nine months as commander, Richards oversaw the bloodiest year in Afghanistan since 2001. About 4,000 people died in insurgency-related violence in 2006, according to an Associated Press count based on numbers from U.S., NATO and Afghan officials.

Richards also was a prominent backer of a controversial peace plan in the southern town of Musa Qala. Under that October deal between the government and village elders, NATO, Afghan and Taliban soldiers were not allowed into the town. But that agreement apparently fell apart on Wednesday and Thursday, when an estimated 200 Taliban fighters overran Musa Qala.

Only 90 minutes before the handover ceremony on Sunday, a NATO airstrike killed a Taliban leader riding in a car near Musa Qala, spokesman Col. Tom Collins said.

Collins said the Taliban leader was killed within that 3-mile zone with the approval of the Afghan government. He said no NATO or Afghan forces were on the ground in Musa Qala.

Collins didn't immediately name the person killed in the strike, but Mohammad Wali, a Musa Qala resident, said the airstrike killed a Taliban leader named Mullah Abdul Gafoor and some of his associates while they were riding in a truck through a small village just outside Musa Qala.

Another resident, Lal Mohammad, told The Associated Press on Saturday that the fighters in Musa Qala were being led by Gafoor, the hardline militia's corps commander in western Afghanistan during the Taliban regime.

Richards also oversaw NATO's largest-ever ground battle, a fight in southern Afghanistan in September to oust between 1,000 and 2,000 Taliban fighters who had massed for an assault on Kandahar city, the Taliban's former stronghold.

"There was last year some skepticism about NATO," Richards said at the ceremony Sunday. "Today that has gone."

The Taliban made a "good attempt" at an offensive last fall but failed and won't again try to take on NATO troops in a mass battle, Richards said in an interview on Saturday.

Richards in September warned that Afghanistan was at a tipping point and that if life did not improve for Afghans over the winter many would switch their allegiance to the Taliban.

He said he is now optimistic NATO will succeed and that he was "delighted" that his warning may have spurred the U.S., Britain and Poland, among other nations, to commit more troops and money.

Along with the additional 3,200 troops, the Bush administration last month said it would ask Congress for $10.6 billion to train and equip the Afghan army and for reconstruction.

Visit FOXNews.com's Afghanistan Center for complete coverage.