President Pervez Musharraf has angrily rejected allegations that Pakistan's intelligence service has indirectly helped the Taleban and al-Qaeda.
In a BBC TV interview, Gen Musharraf said Pakistan was doing an "excellent job" in tracking down militants.
The claims are in a document written by a researcher working for the UK's defence ministry.
It says Pakistan is on the edge of chaos and that the Iraq war had helped extremists recruit people.
The UK Ministry of Defence (MoD) paper says Pakistan's intelligence service, ISI, indirectly backs terrorism by supporting religious parties in the country.
But an MoD spokesman said "the academic research notes quoted in no way represent the views of either the MoD or the government".
Gen Musharraf spoke to the BBC's Newsnight programme ahead of a meeting in Washington with US President George W Bush and Afghan leader Hamid Karzai.
He said that he was "fully satisfied" with Pakistan's co-operation in the fight against terrorism.
"There is perfect co-ordination going on - intelligence and operational co-ordination at the strategic level, at the tactical level," he said.
And he rejected the suggestion in the report that the ISI should be dismantled.
"I totally, 200% reject it. I reject it from anybody - MoD or anyone who tells me to dismantle ISI.
"ISI is a disciplined force, breaking the back of al-Qaeda. Getting 680 people would not have been possible if our ISI was not doing an excellent job."
The Pakistani president rejected allegations by the Afghan leader that Pakistan was not doing enough to fight extremism in its border region, calling Mr Karzai someone who "can't even get out of his office".
He also refused to withdraw his statement that then US Deputy Secretary of State Richard Armitage threatened to bomb Pakistan "back to the stone age" unless it co-operated with America in the wake of the 11 September 2001 attacks.
The report said the Iraq war had radicalised disillusioned youth
"I don't withdraw the claim at all," he said. "Why should I withdraw it now that Mr Armitage is denying it?"
The research paper is understood to have been written by a man with a military background who is linked to the UK's Secret Intelligence Service.
On Afghanistan, the paper said the UK went in "with its eyes closed", and revealed that a secret deal to extricate UK troops from Iraq so they could focus on Afghanistan failed when British military leaders were overruled.
The paper also said that the Iraq war had "acted as a recruiting sergeant for extremists across the Muslim world".