The exclusive report by CNN's Wolf Blitzer on "The Situation Room" said Richardson was invited by the Cuban government for the specific mission of trying to negotiate the release of Gross. Richardson is expected to spend "the next few days" in Havana, Blitzer reported.

"We are aware of Gov. Richardson's trip to Cuba and have been in contact with him," State Department spokeswoman Victoria Nuland told CNN. "While Governor Richardson is traveling as a private citizen, we certainly support his efforts to obtain Alan Gross' release."

A statement issued Wednesday on behalf of the Gross family said, "We are pleased that the Cuban government invited Gov. Richardson to Havana."

"We welcome any and all dialogue that ultimately will result in Alan's release," the statement said. "We are grateful to Governor Richardson for his continued efforts."

Last month, Cuba's highest court upheld the 15-year sentence imposed on Gross for trying to set up illegal Internet connections on the island, according to Cuban state media reports.

Gross, 62, was jailed in December 2009 when he was working as a subcontractor on a U.S. Agency for International Development project aimed at spreading democracy and deemed illegal by Cuban authorities.

Gross says he was trying to help connect the Jewish community to the web and was not a threat to the government.

The case plunged U.S.-Cuba relations to a new low after signs of thawing when President Barack Obama took office. The State Department has said no progress will be made until Gross is released.

Former President Jimmy Carter visited Cuba earlier this year and tried to secure the aid worker's release on humanitarian grounds, arguing that Gross' mother and daughter are battling cancer. But he went home empty-handed.

U.S. officials say they hope the Cuban government will consider releasing Gross early now that the courts have had their say.

The Gross family statement expressed hope that Richardson and Cuban authorities "are able to find common ground that will allow us to be reunited as a family before the Jewish High Holy Days," which begin on September 28 this year with the Jewish New Year of Rosh Hashana.