The Bush administration has denied giving any instruction to former deputy secretary of state Richard Armitage to threaten Pakistan with bombings after the September 11 attacks.

"There was no instruction given to Armitage, and it's never been a matter of US policy to threaten military action or bombing of Pakistan," State Department acting spokesman Tom Casey said on Friday.

Casey said official records showed 'no indication that any kind of comment like that was made'.

However, the spokesman said diplomatic exchanges will remain private and classified and no public readout is possible.

"I have gone back and looked at the official records we have on those conversations, and there's certainly no indication that any kind of comment like that was made," the deputy spokesman said. "We generally don't make public readouts of diplomatic exchanges. But, again, I can assure you that there's nothing in there that would indicate any kind of threat."

Meanwhile Armitage also denied that he had threatened US bombings of Pakistan after the September 11 attacks unless it stopped supporting the Taliban and helped hunt down Osama bin Laden.

But the former senior administration official acknowledged that a blunt message was delivered to the Pakistanis -- that on the subject of terrorism there are no negotiations.

Pakistan President Pervez Musharraf [Images] told CBS News that Armitage made the threat to Pakistan's intelligence director.

"Listen, I've never made a threat in my life that I couldn't back up. But since I wasn't authorised to say such a thing, I couldn't back up that threat. I never said it," Armitage told CNN.

"I did have a long and interesting conversation with the Lieutenant General Mahmoud of Pakistani intelligence, and it was quite strong. And I wanted to make sure he understood the depth of our feelings about what had happened," he said replying to a question on how he could have been misconstrued.

Armitage pointed out that the conversation with General Mahmud was pretty straightforward and he was embarrassed to cut off the Pakistani intelligence shief.

"I told him that, for Americans, this was black or white; that Pakistan was either with us fully or not. It wasn't a matter of being able to negotiate. He started to tell me about the history of Pakistan-Afghan relations. And I must say I'm a little embarrassed, I cut him off and said, history starts today, General, and Secretary Powell and I will be presenting you with a list of requirements for Pakistan tomorrow. We would like you to go and consult with President Musharraf," Armitage said.

Asked if he felt the wording of the conversation with General Mahmud was effective at the end of the meeting, Armitage replied, "Mahmoud came back the next day and said that General Musharraf had agreed and wanted to see our requirements. So, I guess that's the best measure of effectiveness."