The US has cut $33m in aid in response to the imprisonment of Dr. Shakil Afridi by Pakistan.
A Senate panel has said US aid will be cut by $1m for every year of Dr. Afridi’s sentence.
Dr Afridi was sentenced to at least 30 years in prison for treason. He has been found guilty of assisting the CIA in locating Osama bin Laden.
The cuts in aid are part of a bill sending $1bn worth of aid to Pakistan.
"We need Pakistan, Pakistan needs us, but we don't need Pakistan double-dealing and not seeing the justice in bringing Osama Bin Laden to an end," said Republican Senator Lindsey Graham.
Secretary of State Hillary Clinton also criticised the sentencing.
"The United States does not believe there is any basis for holding Dr [Shakil] Afridi. We regret the fact that he was convicted and the severity of his sentence,“ she told reporters on Thursday.
But Pakistan defended the jailing and said any country in its position would have acted the same if one of its citizens was found to be working for another state’s intelligence service.
“I think as far as the case of Mr Afridi is concerned, it was in accordance with Pakistani laws and by the Pakistani courts, and we need to respect each other's legal processes," Pakistani Foreign Ministry spokesman Moazzam Khan told reporters on Thursday.