Tropical fruit trees and trim gardens greet visitors to Ernest Hemingway's sprawling estate on the outskirts of Havana, but the wooden house where he lived for more than 20 years is falling apart, damaged by erosion, tropical humidity and botched repairs.

American preservationists are seeking to save the house, but they have run up against the politics dividing the U.S. and Cuban governments.

The Bush administration has taken a tough stance toward the communist-run island, tightening long-standing trade and travel restrictions. As a result, the preservationists were denied a license to travel to Cuba last year.

However, the Hemingway Preservation Foundation in Concord, Mass., joined forces with the National Trust for Historic Preservation in Washington to reapply for the license, this time successfully. The groups plan to send a team of architects and engineers to Cuba to study the condition of the estate, which is called Finca Vigia, or Lookout Farm. The trust also put the house on its list of most endangered places, the first time it has done so for a site outside the United States.

Lookout Farm is where Hemingway -- "Papa" to his friends -- lived from 1939 to 1960 and wrote "The Old Man and the Sea." Since the writer's suicide in 1961, the hacienda has served as a rare cultural bridge for Cubans and Americans.

The Hemingway Preservation Foundation is urgently trying to raise $150,000 to fund the study, said its executive director, Mary-Jo Adams. The rehabilitation will cost millions of dollars, and the license the group has been granted does not allow it to import the necessary materials, she said.

With the Americans' arrival delayed, the Cubans launched their own projects. Renovation of the living room, bathroom and writing room began in December, and pieces of furniture and personal items were removed to prevent further water damage. Roof repairs to stop leaks are also underway.

Gladys Rodriguez, a Cuban museum expert and Hemingway scholar, said she was determined not to let politics slow things down. "We can't just stop working on this," she said.

Documents in the home have fared best because Americans and Cubans have worked together since 2002 to preserve thousands of letters, manuscripts and photographs. The originals remain at the hacienda, but microfilmed copies will go to Boston's John F. Kennedy Library Foundation, which has the world's primary collection of Hemingway documents. "This is technology that will last 500 years," said Susan Wrynn, the foundation's Hemingway curator.

The sound of chirping birds and the rich scent of flowers permeate the hacienda. "The air is different here," said Sandra Spanier, an American scholar who is editing a 12-volume collection of Hemingway's letters. "You can just imagine what a wonderful retreat this was for someone whose fame was so quickly catching up with him."