Pakistan insisted today that it never gave the United States permission to chase Taliban and al Qaeda fighters from Afghanistan into Pakistan.

"Absolutely not. The Americans cannot cross the Pakistani border from Afghanistan to chase what they say are vestiges of Taliban and al Qaeda," Information Minister Rashid Ahmed said.

The assertion directly contradicts American assertions that U.S. troops could cross the border if they were in hot pursuit of suspects.

A U.S. military spokesman, Maj. Stephen Clutter, said Friday that American forces "reserve the right to go after them and pursue them." He said that notion was "something that Pakistan is aware of," though he said U.S. forces hadn't gone into Pakistani territory.

As early as last March, U.S. commanders said their troops might enter Pakistan, but only as a last resort and with Pakistan's approval.

Pakistani Foreign Minister Khursheed Kasuri also weighed in on the dispute today.

"From the very first day, it has been absolutely clear and fully understood . . . that operations within Pakistani territory would be conducted solely and exclusively by our own forces and in response to decisions taken by Pakistan," he said in a written statement.

But officials emphasized that Pakistan had no intention of ending its backing for U.S.-led forces mopping up remnants of Afghanistan's former rulers.