Former New Mexico Gov. Bill Richardson has arrived in Cuba where he is trying to win the release of a U.S. citizen who has been detained since December 2009.

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

Nuland said there are no U.S. officials traveling with the former governor (and former U.S. ambassador to the United Nations, U.S. congressman and Energy Secretary) and he is not carrying any messages from the administration.

Gross’ lawyer, Peter Kahn, said in a statement on behalf of the Gross family that he is hopeful the Cuban government will release him.

“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. We are grateful to Gov. Richardson for his continued efforts. We hope that the governor 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,” Kahn said of Rosh Hashanah, the Jewish New Year that starts Sept. 28 at sundown.

Gross worked as a contractor for the United States Agency for International Development and was detained in Cuba in December 2009 after distributing satellite communications equipment to the island’s Jewish population without permission from the Cuban government. He was sentenced to 15 years in prison earlier this year and Cuba’s Supreme Court upheld the decision last month.

Gross’ family has appealed for his release on humanitarian grounds. He suffers from diabetes and is said to have lost much weight in prison. His wife and daughter have also had medical problems in the past year.

Richardson, who also tried to run for president in 2008, has in the past been able to secure the release of several other Americans detained abroad. In 1996, he negotiated the release of a U.S. pilot who, along with other Red Cross workers, had been taken hostage in Sudan. In 2008, he again won the release of a U.S. journalist detained in Sudan. He has also secured the release of Americans in Iraq and North Korea and was involved in discussions to release Americans held in Colombia and Kashmir.