The Cuban government has rebuffed a mission by former New Mexico governor Bill Richardson to free a U.S. government contractor jailed in Havana, even ruling out a visit with the man, Richardson said Sunday.

Richardson vowed to remain in Cuba until he was allowed to see jailed American Alan P. Gross.

“We were supposed to leave yesterday. We’ve extended our stay in the hotel. My position is, I’m not planning to leave until I get a chance to visit Alan Gross,” Richardson said in a telephone interview from Havana.

Cuba’s action appeared to be an extraordinary snub of the prominent, Spanish-speaking Democrat and former U.N. ambassador who has had cordial relations with the island’s government. There was no word from the Cuban government on why Richardson couldn’t see Gross, who has routinely received visits from U.S. diplomats and members of Congress.

Gross, 62, was arrested in December 2009 while working on a secretive democracy program in Cuba for the U.S. Agency for International Development. His detention has grown into a major impediment to President Obama’s goal of improving relations with Cuba.

Alan Gross is being held in a Cuban jail. (Alan Gross/ Courtesy Gross family)

Richardson, who has long supported improved relations with Cuba, said he was “flabbergasted” by his treatment. He was invited to Havana by the Cuban government to discuss the Gross case, he said, leading to hopes of a breakthrough. Cuban parliament leader Ricardo Alarcon last week described Richardson’s trip as “noble.”

But Richardson said there appeared to be disagreements within the Cuban government on what to do with Gross.

“My sense is, there are some elements in their government that don’t want to improve relations with the U.S.,” Richardson said.

While Richardson traveled as a private citizen, his trip was welcomed by the State Department, which briefed him before he set out on Sept. 7. In a meeting Thursday, Richardson conveyed to Cuban Foreign Minister Bruno Rodriguez the U.S. position that “if you release Alan Gross, there are a number of areas of cooperation we can talk about,” Richardson said.

But “their inclination is not to do that,” he said.

The Obama administration has eased some Cuba travel and financial restrictions imposed by President George W. Bush. But further cooperation on matters such as immigration, the environment and drug trafficking has stalled, officials say. In addition, Cuba is unlikely to get its wish to be removed from the U.S. list of terror-sponsoring countries while Gross is held, American officials say.

American diplomats had hoped Cuba would deport Gross after he was sentenced in March to 15 years in prison. They say Cuban authorities have never explicitly asked for anything in exchange for his release. But Cuban authorities have been angered by the Obama administration’s continuation of the secretive democracy program on the island, which had grown significantly under Bush, analysts say.

The Obama administration defends the program as part of a global effort to support basic freedoms. The 2011 budget provides $20 million for the Cuba effort, up from $15 million the previous year.

Cuba considers the democracy-promotion activities illegal, since they fall under the Helms-Burton law, which calls for regime change on the island.

Gross was providing satellite phone and computer equipment to the island’s Jewish community, under a $6 million contract won by his employer, Development Alternatives Inc. of Bethesda.

Richardson, a former U.N. ambassador, has spent his career traveling to hot spots such as Iraq, North Korea and Sudan to negotiate the release of jailed Americans.