The White House is calling on Cuba to release American government contractor Alan Gross on the fifth anniversary of his imprisonment.

Gross was detained in December 2009 while working to set up Internet access as a subcontractor for the U.S. Agency for International Development. He was tried and sentenced to 15 years in prison. Cuba regards USAID programs as illegal attempts by the U.S. to undermine the Cuban government.

Gross’ family has said he has threatened to commit suicide if he is not released by his birthday next May.

White House press secretary Josh Earnest says in a press release issued Wednesday that the U.S. remains “deeply concerned” about Gross’ health.

Earnest says Gross’ release “would remove an impediment to more constructive relations between the United States and Cuba.”

(AP)