Pakistan has angrily denounced comments made by the US ambassador to Afghanistan that America may move against "terrorists" based in Pakistan.
Pakistan says it is doing its utmost to stop cross-border attacks
Pakistan's information minister said the army could deal with the problem and the comments were "harmful".
He said Pakistan would never allow foreign troops on its soil.
Islamabad has repeatedly rejected Afghan complaints that it is not doing enough to stop cross-border raids by al-Qaeda and Taleban remnants.
Correspondents say the issue of American troops being deployed in Pakistan is extremely sensitive and likely to be deeply unpopular among most of the public.
US Ambassador to Afghanistan Zalmay Khalilzad sparked the row on Monday when he said that America could not allow "terrorist sanctuaries" in Pakistan to "fester indefinitely".
He said one of the greatest worries for the US was the fact that the Taleban and other hostile groups continue to use Pakistan as a base in which they train and operate.
"We have told the Pakistani leadership that either they must solve this problem or we will do it for ourselves," Mr Khalilzad said in a speech to the Centre for Strategic and International Studies, a Washington think-tank.
Mr Khalilzad said that Washington would prefer Islamabad to deal with the problem, and that the Pakistani government had agreed.
"We are prepared to help President Musharraf," he said, "because one way or another the problem will have to be dealt with."
But Pakistani Information Minister Sheikh Ahmed Rashid said the army was fully capable of "confronting terrorists" and it was not necessary for US troops to cross the border from Afghanistan.
Pakistani troops "have sacrificed their lives in fulfilling their pledge to combat terrorists", he said.
"We do not need anybody in our territories - neither can permission be given to anyone.
"These kind of irresponsible statements can create political problems for us.
"We are the country that has delivered the best results in this war... our progress is far better than anybody."
The information minister also said that there were no training facilities for the Taleban in Pakistan, and that Islamabad supported the government of President Hamid Karzai and shared information with US intelligence.
Pakistani Foreign Ministry spokesman Jalil Abbas Jilani also criticised the ambassador's comments, describing them as "unwarranted".
Pakistan says its forces are confronting the "terrorist" menace
"Perhaps Ambassador Khalilzad is not aware of the position of his government on the subject," he said, "which greatly appreciated Pakistan's efforts in eliminating and rooting out the terrorists' infrastructure."
It is not the first time that the US Afghanistan ambassador has been at the centre of a row - last month he also irritated Islamabad by saying that al-Qaeda fugitives were launching attacks into Afghanistan from Pakistani soil.
The war of words comes as the US steps up patrols along the rugged border of Afghanistan with Pakistan in an attempt to catch al-Qaeda and Taleban militants.
Last month, Pakistan launched a huge offensive against suspected militants, and tribesmen sheltering them, in the semi-autonomous area of South Waziristan. It says more than 60 suspects were killed and 160 captured.