Updated

Al-Qaida has urged the family of an American aid worker it abducted in Pakistan three years ago to demand that the U.S. government negotiate for his release.

Warren Weinstein was abducted in August 2011, four days before his seven-year stint as a business development expert with the USAID was to end. He turned 73 in July.

Al-Qaida says it's "not interested in keeping" Weinstein but wants to exchange him for prisoners in U.S. custody.

It criticizes the U.S. government over alleged "inaction" and for not contacting al-Qaida to negotiate for Weinstein's release.

The authenticity of the message could not be independently confirmed but it was posted on a website commonly used by militants.

The White House has called for Weinstein's immediate release but has said it won't negotiate with al-Qaida.