A Cuban Foreign Ministry official rejected claims by the wife of Alan Gross that the jailed American contractor was in ill health and said Cuba was willing to negotiate his release with U.S. officials.

“The state of health of Mr. Gross continues being normal and he regularly does intense physical exercises,” Foreign Ministry official Josefina Vidal said in a statement Sept. 12.

Vidal added that Cuba reiterates its willingness “to find a solution in the case of Mr. Gross and continues to await an answer,” The Associated Press reported.

Gross, 63, of Potomac, Md., was sentenced last year to 15 years in prison for “crimes against the state.” He was arrested in 2009 for allegedly bringing satellite phones and computer equipment to members of Cuba’s Jewish community.

Jared Genser, an attorney for the Gross family, said in a statement released Thursday that the Cuban government has not worked to resolve the case.

“If Ms. Vidal is serious, I would urge her to convey through diplomatic channels a clear proposal to initiate meaningful discussions with the United States to secure Alan’s release,” the statement read.

Judy Gross said in a statement released by the family’s lawyers Sept. 11, just after she returned from a four-day trip to Cuba, that “While his spirit remains strong, I fear he is not going to survive this terrible ordeal.”

Gross reportedly has lost more than 100 pounds since his arrest and his family says he is suffering from degenerative arthritis. His mother is dying and one of his daughters is battling cancer.

Cuban officials say they have suggested previously a prisoner swap in which Gross would be exchanged for five Cuban spies, four of whom have been jailed in the United States on spying charges for 14 years. One of the convicted spies was allowed to return to Cuba last year to serve out his three-year probation period.