WASHINGTON: The White House urged Pakistan on Wednesday to release Dr Shakil Afridi, minutes before Prime Minister Nawaz Sharif arrived at the official residence of the US president for talks on key issues.

The physician, who helped CIA trace Osama bin Laden, has been imprisoned for a crime he allegedly committed before the US raid on Bin Laden`s compound in Abbottabad.

As the prime minister`s party arrived at the White House, Press Secretary Jay Carney told reporters that President Barack Obama would be pressing for Dr Afridi`s release.

He argued that the doctor`s imprisonment was unjust and unwarranted.

`Our position on Dr Afridi has long been clear, and Fm sure we will again make it clear during this visit. We believe his treatment is both unjust and unwarranted. He should be released,` Carney said in response to a question.

`Bringing Osama bin Laden to justice was clearly in Pakistan`s interest, and the prosecution and conviction of Dr Afridi sends exactly the wrong message about the importance of this shared interest. So this is something that we have, in a sustained way, madeclear to Pakistan and will continue to, including during this visit,` Carney said.

The issue was also raised by top US lawmakers when Mr Sharif met them on Tuesday.

The prime minister told the Congressmen that Dr Afridi was `not a hero` and his fate would be decided by courts.

Earlier on Wednesday, Vice President Joe Biden reaffirmed the US desire to strengthen relations with Pakistan during a meeting with Prime Minister Sharif.

Mr Biden, who hosted breakfast this morning for Mr Sharif at his residence, also congratulated the prime minister on his historic election in May, `which led to the first democratic transfer of power between elected governments in Pakistan`s history`, said a statement issued by his office.

Mr Biden also reaffirmed the US `commitment to strengthening bilateral ties in support of a strong, democratic, prosperous Pakistan`, the statement said.

The US vice president affirmed to the prime minister that together `we must continue to combat terrorism and violent extremism and work to strengthen regional and global security`