WASHINGTON, May 27: The sentencing of Dr Shakil Afridi, who had helped the CIA trace Osama bin Laden, would not restore normal relations between the United States and Pakistan, US Defence Secretary Leon Panetta said on Sunday.

In an interview to ABC News, Mr Panetta also said that the US-Pakistani relationship remained “one of the most complicated we've had.”

Mr Panetta refused to accept Pakistan’s claim that by working for a foreign spy agency, Dr Afridi had committed treason.

“It is so difficult to understand, and it’s so disturbing that they would sentence this doctor to 33 years for helping in the search for the most notorious terrorist of our times,” Mr Panetta said.

Dr Afridi “was not working against Pakistan. He was working against Al Qaeda,” he added.“I hope that ultimately Pakistan understands, that…what they have done here…does not help to try to re-establish a relationship between the United States and Pakistan.”

The sentencing has posed a new challenge to an already tense relationship between the two countries, Mr Panetta said, adding: “It’s an up-and-down relationship. They’re dealing with the terrorist threat just like we are.”

The US, however, would “keep pushing” Pakistan to “understand how important it is for them to work with us to try to deal with the common threats we both face”, he said.

Responding to Pakistan’s demand for a higher transit rate for reopening ground supply routes to Afghanistan, Mr Panetta said: “We're going to pay a fair price. We're not about to get gouged in the price. We want a fair price.”

Pakistan closed the supply routes about six months ago over the US air raid that killed its soldiers but indicated last week it is willing to reopen if the United States paid a higher transit rate.

Mr Panetta has also rejected Pakistan’s demand to stop drone strikes on targets inside its tribal territory.

Asked about air strikes targeting Al Qaeda operatives in Yemen, Mr Panetta said that armed drones were “one of the most precise weapons that we have in our arsenal.”

Meanwhile, White House Deputy National Security Advisor Ben Rhodes rejected Bilawal Bhutto Zardari’s demand that the US should apologise for the Salala attack in which 24 Pakistani soldiers were killed.

“I wouldn't have anything new to offer on that beyond what we have said, which we deeply regret the incident. We have thoroughly investigated it. We shared the results of that investigation with the Pakistanis,” he told a briefing in Washington when asked to comment on the demand.