Troops searching for Osama Bin Laden along Pakistan's border with Afghanistan have no idea where he is, says Pakistan leader Pervez Musharraf.
Osama Bin Laden - top of America's "Most Wanted" list
Recent intelligence proved that the al-Qaeda leader was alive, Gen Musharraf told the Washington Post, but "we don't know where he is."
Thousands of Pakistani troops have been deployed in the border areas.
Gen Musharraf, a key ally in the war on terror, is now in the UK after talks in Washington with President Bush.
In an interview published on Sunday, Gen Musharraf admitted there were no active leads on the whereabouts of the al-Qaeda leader.
Any suggestion of Bin Laden's location would be a guess, he said.
Pressed by the Washington Post on whether the trail had gone cold, he said: "Yes, if you mean we don't know, from that point of view, we don't know where he is."
But he said the US shared responsibility, because the US-led coalition did not have sufficient troops in Afghanistan, which had left "voids".
He called for recruitment and training for the Afghan army to be stepped up.
Gen Musharraf also denied reports that Pakistani troops were being pulled back from the mountainous South Waziristan tribal area, long suspected as a possible hiding place for Bin Laden and his deputy Ayman al-Zawahiri.
The three-year hunt for the al-Qaeda leader is one of the most sensitive issues between Pakistan and the US but Mr Bush was full of praise for Gen Musharraf.
"His army has been incredibly active and very brave in southern Waziristan, flushing out an enemy that had thought they had found safe haven," Mr Bush said after their talks on Saturday.
Correspondents say that US officials have sought to play down Bin Laden's significance in the wider war on terror - a change in their stance in immediate aftermath of the 11 September attacks.
At the time, President Bush declared that there was no hiding place for the al-Qaeda leader who was "Wanted: Dead or Alive".
The last appearance of Bin Laden was just before the US election on 2 November, in a videotape in which he threatened fresh attacks on America whoever was elected.
He appeared in good health in the tape but it was not clear when it was recorded.