HAVANA (AP) — Cuba accused the United States of lying about the health and conditions of confinement of a jailed American government subcontractor, and pushed back Wednesday against an apparent UN ruling that his 15-year sentence is arbitrary and a violation of his human rights.

Josefina Vidal, the top Cuba diplomat for North American affairs, also said it was unrealistic to expect Cuba to free Maryland resident Alan Gross “unilaterally” — a clear demand for US concessions in the case of five Cuban intelligence agents sentenced in Florida to long prison terms.

The US government “is directly responsible for the situation that led to the detention and judgment and trial of Mr. Alan Gross, so we have to sit down together, to look together for a solution to this case,” she said.

Vidal said Cuba had received word from the UN Working Group on Arbitrary Detention on Tuesday that it ruled in Gross’ favor, though the decision had not yet been made public.

While the ruling is a public relations hit to Cuba, the body has no enforcement powers. Vidal said the same agency determined in 2005 that the US jailing of the five Cuban agents was arbitrary.

‘The US government is lying once again to the public, saying that Mr. Gross has cancer and does not receive adequate medical care’

Vidal said Cuba has repeatedly made its terms known to US officials and has not gotten a response. Diplomats and the White House have flatly ruled out a prisoner swap, at least in public comments.

Gross told a US rabbi who visited him last week at a military hospital where he is being held that he does not want to be linked to the intelligence agents’ cases since he does not believe he committed espionage. But he added that he does desire better US-Cuban ties and freedom for all “political prisoners.”

Gross’ champions say Cuba’s insistence on an exchange amounts to holding the 63-year-old hostage. The case has chilled already frosty relations between the two nations.

Gross was setting up wireless Internet connections for Cuba’s Jewish community as a subcontractor for USAID, the US government agency in charge of foreign economic development, when he was arrested in December 2009. The project he was working on was part of a $40 million-a-year program to promote democracy.

US officials have portrayed the work as purely humanitarian. But Gross was violating Cuban law by doing work for USAID in the country, since such activities must be authorized on the Communist-run island. Gross’ wife acknowledged in a recent lawsuit against the US government and her husband’s employer that he knew the work he was doing was risky, and other documents show he took steps to conceal his activities.

Gross, who was overweight before his arrest, has lost 105 pounds in custody and suffers from a number of ailments. Earlier this year, he developed a mass behind his right shoulder. His lawyers have called on Cuba to allow an independent doctor of his choosing to examine him.

Vidal reiterated that a team of Cuban doctors performed a biopsy and found no evidence that the growth was cancerous. She hinted that Cuba would release more tests if the accusations by US political and diplomatic officials continue.

Gross’ champions say Cuba’s insistence on an exchange amounts to holding the 63-year-old hostage

“The US government is lying once again to the public, saying that Mr. Gross has cancer and does not receive adequate medical care,” she said. “These lies have not stopped, even after the results of the biopsy conducted on the lesion on his back were delivered to his family and US authorities.”

Gross’s lawyer, Jared Genser, scoffed at the Cuban diplomat’s complaints.

“Ms. Vidal asserted today the US government is ‘lying’ about Alan Gross’ health,” he said. “That is an absurd statement.”

A resolution demanding Gross’ release was introduced in the US Senate this week and was expected to pass.

On Monday, White House press secretary Jay Carney reiterated Washington’s demand that Cuba release Gross, or at least allow him to travel to the United States to visit his elderly mother, who was diagnosed with inoperable cancer.

Vidal repeated Cuba’s position that such a trip was not in the offing.

Recently, Gross’ wife Judy filed a $60 million lawsuit against the US government and the company that hired him, alleging they did not train him properly or make him aware of the risks he was running in Cuba.

However, Vidal said Gross knew perfectly well that his activities were illegal, and that he was being paid handsomely for the risk he was taking.

“Mr. Gross violated Cuban law by committing acts that constitute serious crimes which are severely punishable in most countries, including the US,” she said.