The NATO-led International Security Assistance Force, or ISAF, took over from a U.S.-led anti-terror coalition that was first deployed nearly five years ago to unseat the Taliban.

It will be the first time NATO has conducted land combat operations. The force will be more than twice the size of the coalition presence in the south last year and will boost the number of ISAF troops across the country to about 18,000.

In a statement Monday, NATO Secretary General Jaap de Hoop Scheffer warned that Afghanistan could again become a breeding ground for terrorists without greater international help.

NATO takes over with fighting on the rise, especially in the south. In the latest violence there, 30 suspected Taliban were killed over the weekend.