Alan Gross and his wife Judy
Alan Gross and his wife Judy Reuters

President Barack Obama has for the first time publicly acknowledged that the United States is negotiating with Cuba for the release of Jewish-American contractor Alan Gross through a “variety of channels.”

In an interview with the Fusion network, a sister network to ABC News, Obama said, “We’ve been in conversations about how we can get Alan Gross home for quite some time.”

Gross is being held on espionage charges in Havana for the past five years, and sources who have visited with Gross recently told ABC News his health has vastly deteriorated.

He has lost all but one of his front teeth, can barely walk because of hip damage, and is blind in one eye, according to the report.

“We continue to be concerned about him. We think that he shouldn’t have been held in the first place,” Obama said in the interview.

“With respect to Cuba generally, I’ve made very clear that the policies that we have in making remittances easier for Cuban families, and making it easier for families to travel, have been helpful to people inside Cuba... But the Cuban government still needs to make significant changes.”

Last week Press Secretary Josh Earnest said the detention of Gross has been a barrier to more constructive talks with the island nation.

"The Cuban government’s release of Alan on humanitarian grounds would remove an impediment to more constructive relations between the United States and Cuba," he said.

Sources have told ABC News previously that the Obama administration takes seriously promises by Gross to not spend another year in the Cuban military hospital and to begin a possible death inducing hunger strike by the end of this year, and is looking for a solution with the Cuban government.

Gross, 65, was sentenced to 15 years in prison in Cuba in 2011 after being convicted of "acts against the independence or territorial integrity of the state" for allegedly distributing communications equipment as a contractor for USAID.

Gross ended an eight-day hunger strike on April 11 to press for his release from prison. That hunger strike ended after a telephone conversation with his mother, who passed away two months later.

The Cuban government has expressed its willingness to free Gross in exchange for the United States free the so-called “Cuban Five”, intelligence agents convicted in a 1998 U.S. spy case.   

Havana acknowledges the five men - two of whom have been released after serving their sentences - were agents but says they were spying on "terrorist" exiles and hails them as national heroes. 

Secretary of State John Kerry has said in the past that Washington would work to free Gross but outright rejected a deal with Havana to swap him for the five Cuban spies.

Relations between the U.S. and Cuba have been frozen since Fidel Castro's communist revolution in 1959. The U.S. has maintained sanctions on the communist regime throughout the decades, particularly given Cuba's poor human rights record.

Nevertheless, at a memorial ceremony last year for late South African leader Nelson Mandela, Obama made a surprise move on his way to the podium by greeting Cuban President Raul Castro with a long handshake and smile.

The handshake was criticized by Republicans, with Arizona Senator John McCain saying it was a mistake to "shake hands with somebody who is keeping Americans in prison," a likely reference to Gross.