NATO prevented a planned Taliban attack on the 10th anniversary of Sept. 11, the military alliance claimed Thursday.

British Army Major General Tim Evans, who heads the International Security Assistance Force Joint Command (ISAF) in Afghanistan, said that the insurgent group had planned a large-scale attack on the country, but NATO forces stopped it.

We do believe that [Taliban forces] were trying to do an attack on the anniversary of 9/11 and actually we thwarted a number of attacks, he told a teleconference with reporters at the Pentagon.

On Tuesday, Taliban-linked fighters believed to be part of the Haqqani network did stage an attack on the Afghan capital of Kabul, killing 15 people. In a siege that lasted 20 hours, militants fired rockets and machine guns at the U.S. embassy and attacked a number of other targets.

It was reported that the insurgents attacked NATO headquarters, as well as police stations and the Kabul airport. Additionally, ISAF officers stopped at least three suicide bombers.

They did not breach any of the compounds of either the [U.S.] embassy, ISAF, or any of the government buildings, Evans added.

The general saw the Tuesday attack as a sign that the Taliban was drastically weakened, and is changing their tactics.

They've lost ground in central Helmand, they've lost ground in Kandahar, and therefore that's why they've had to change their tactics, he said. They haven't got that same initiative that they had before.

U.S. Ambassador to Afghanistan Ryan Crocker also downplayed the events, despite the fact that U.S. embassy was hit by six rocket-propelled grenades.

This really is not a very big deal, a hard day for the embassy and my staff who behaved with enormous courage and dedication, Crocker told reporters Wednesday.

If that's the best they can do, you know, I think it's actually a statement of their weakness and more importantly, since Kabul is in the hands of Afghan security, it's a real credit to the Afghan National Security Forces, he said.