The latest charges came as Karzai prepared for talks at the White House today with U.S. President George W. Bush -- and ahead of a meeting there on September 27 between Bush, Karzai, and Musharraf.
The latest allegations made about Pakistan by Karzai focus on Islamabad's failure to close down Pakistan's most radical madrasahs -- the religious boarding schools for poor children where, in the most extreme cases, Islamic militancy is encouraged.
Karzai made the remarks after a speech on September 25 in Washington. He said many madrasahs in both Afghanistan and Pakistan teach violent hatred of those whose beliefs differ from a strict interpretation of Islam.
"Those places have to be closed by action, by arresting the [operators] -- the masters of those madrasahs, the organizers -- by simply closing them down," Karzai said. "And I hope President Musharraf and I and those who help us around can address the problem effectively by going and simply closing them." Finger Pointing
Karzai raised the issue of extremism within Pakistani madrasahs after Musharraf told the United Nations General Assembly in mid-September that support for the Taliban in his country comes from some of the millions of Afghan refugees there.
"Problems along the bordering regions of Pakistan and Afghanistan are compounded by the continuing presence in Pakistan of over 3 million Afghan refugees, some of them sympathetic to the Taliban," Musharraf told UN delegates.
In the week since that UN speech, Karzai has responded to Musharraf's finger pointing by charging that Taliban commanders are now headquartered in the Pakistani city of Quetta -- and that they command Taliban attacks inside Afghanistan from safe havens there.
The escalating argument between Karzai and Musharraf is expected to dominate talks at the White House on September 27 when the two sit down with Bush.
Even as Karzai was meeting with Rumsfeld on September 25, Musharraf was staking out his position -- which he made public in a speech to the Council on Foreign Relations in New York. Musharraf told that audience that it is impossible for Taliban leaders to have their headquarters in Quetta.
"[Pakistani officials] have been informed that both NATO and the U.S. forces in Afghanistan have determined that the Taliban leadership is sitting in Quetta [Pakistan], and is operating the war from Quetta."
"Quetta is the capital of Baluchistan," Musharraf said. "Quetta has today a provincial assembly functioning. We have a military corps headquartered there with two divisions there. There is no question that any Taliban headquarters there. This is the most ridiculous statement and it is the most ridiculous that the Taliban headquarters can be in Quetta."
Some independent experts on Pakistan disagree. Mounting Pressure
Ahmed Rashid, the Pakistani journalist who documented the rise of the Taliban movement during the 1990s in his book "Taliban," told RFE/RL that allegations about Taliban headquarters in Quetta are not coming from Kabul alone. He said the allegations also have been made privately to Musharraf by NATO and the U.S. military.
"[Musharraf] is now aware and the Pakistanis are aware," Rashid said. "They have been informed that both NATO and the U.S. forces in Afghanistan have determined that the Taliban leadership is sitting in Quetta, [Pakistan], and is operating the war from Quetta. I think there is now an enormous amount pressure on Musharraf to do something about that."
Karzai also has accused Pakistan of ignoring Afghan intelligence passed on recently to Islamabad -- including the phone numbers and precise locations of Taliban leaders who had used those telephones.
But Musharraf told a New York audience that the value of the Afghan intelligence was questionable because it was too old.
"Intelligence -- to be effective -- should be immediate. Nobody, no target, sit there waiting for you for three months [saying], 'Come and catch me,'" Musharraf said. "If you give telephone numbers which are three to six months old, this becomes ridiculous. And this is exactly what happened. [Karzai] gave these numbers to me when he came [to Pakistan] with his intelligence boss also sitting on a presidential visit. And he handed over this file to me. Right in front of him I actually was extremely rude to his intelligence boss. I said: 'Is this your sense of intelligence that your were waiting for a presidential visit to hand over this file of numbers to me?'"
The release in the United States on September 25 of Musharraf's memoirs, "In The Line of Fire," also has given Musharraf a chance to influence the public debate about Pakistan's contribution to the counterterrorism effort before he sits down with Bush and Karzai in Washington.
In his book, Musharraf reportedly concedes that Al-Qaeda and Taliban militants still operate in his country. But he insists that he has no knowledge of the whereabouts of high-profile fugitives like Osama bin Laden or Taliban leader Mullah Mohammad Omar.
(RFE/RL correspondent Andrew Tully contributed to this report from Washington.)