Pakistan has angrily rejected claims from the US that the senior leadership of al-Qa'ida - presumably including Osama bin Laden and Ayman al-Zawahiri - are holed up in a "secure hideout" inside the country from which they are directing operations and building the strength of their terror network.
The Pakistani reaction came in response to unusually direct claims made in Washington by the outgoing US intelligence chief, John Negroponte, about the whereabouts of the senior al-Qa'ida figures believed to be responsible for the attacks of 11 September.
In his annual assessment of worldwide threats against the US, Mr Negroponte said: "Al-Qa'ida is the terrorist organisation that poses the greatest threat to US interests. They are cultivating stronger operational connections and relationships that radiate outward from their leaders' secure hide-out in Pakistan to affiliates throughout the Middle East, north Africa and Europe."
In private US officials will often claim Pakistan is not doing as much as it can to bring about the capture of the al-Qa'ida leader. But the position usually expressed publicly is that Bin Laden is "on the run", probably in the mountainous border region between Pakistan and Afghanistan.
The statements of Mr Negroponte, who is soon to step down from his position as director of national intelligence to become deputy secretary of state, are the most direct yet and constitute a criticism of Pakistan's military efforts.
A Pakistani military spokesman, Major-General Shaukat Sultan, rejected the claims, saying: "We have no such information nor has any such thing been communicated to us by any US authority." A statement issued by Pakistan's Foreign Ministry said it was committed to fighting terrorism and that its efforts should be recognised. Nonetheless, it is an open secret in Pakistan that much of the Taliban leadership is living in the city of Quetta.
What may be responsible for the change in the US's tone is a truce Parvez Musharraf signed with militants last year in North Waziristan, one of the tribal agencies often described as the most likely hiding places for Bin Laden and Zawahiri. The US has twice launched missile attacks on the tribal area of Bajaur in Pakistan in what was believed to be an effort to target Zawahiri.
In testimony before Congress, Mr Negroponte said some al-Qa'ida figures had been killed but that the network's "core elements are resilient. They continue to plot attacks against our homeland and other targets with the objective of inflicting mass casualties".
He said: "Pakistan is our partner in the war on terror and has captured several al-Qa'ida leaders. However, it is also a major source of Islamic extremism."
Meanwhile, top Congressional Democrats for a second successive day assailed President Bush's plan to send an extra 21,000 troops to Iraq, as Condoleezza Rice prepared to travel to key US allies in the region, including Egypt, Jordan and Saudi Arabia to explain the policy.
At home, Mr Bush was more isolated than ever, with almost two thirds of Americans saying they opposed the latest build-up, according to a new poll.