Cuban President Fidel Castro on Saturday tried to block the departure of two dissident Cuban doctors to the United States, notifying Zimbabwe government officials that his country would issue the pair documents valid to travel anywhere in the world -- except the United States, according to diplomats and officials in Zimbabwe.

Leonel Córdova Rodríguez, 31, and Noris Peña Martínez, 25, had been expected to fly from Harare to Nairobi on Saturday after the United States agreed to offer the Cubans refugee status. The doctors could have arrived in this country as early as today, but remained jailed at the Goromonzi detention center after the last-minute snag.

``There seems to be a wrangle going on between the government of Zimbabwe and the government of Cuba,'' said a Western diplomat closely monitoring the case. ``The Cubans are saying that the doctors can travel anywhere in the world, except the United States.''

HIGH-LEVEL MOVES

The diplomat, who spoke on the condition of anonymity, said Castro appeared to be trying to steer the doctors to Canada as ``a backlash'' against the international condemnation surrounding the doctors' abduction and attempted deportation back to Cuba.

Asked which governments were handling the latest negotiations, the diplomat said: ``Fidel Castro and [Zimbabwean President] Robert Mugabe. It has reached the highest levels.''

U.S. officials refused to discuss the case, pending a breakthrough in the tense talks.

``This is a case in progress, so I am not free to comment,'' said Bruce Wharton, the U.S. Embassy spokesman in Harare.

Princeton Lyman, a former top-ranking State Department official who served as U.S. ambassador to South Africa and Nigeria, said Castro has no legal right to dictate the asylum process.

NO ROLE FOR CASTRO

He likened the situation to the United States asking Iraqi President Saddam Hussein for permission to take in an Iraqi defector.

``It's not up to the Cuban government. It's up to the United Nations and Zimbabwe,'' Lyman said. ``[The doctors] have gone through and met the criteria, so travel documents shouldn't be the issue. The issue is whether Zimbabwe will let them go.''

Reached at a political rally on his cellular phone, Mugabe's spokesman George Charamba said he was aware of the Cuban government's latest communiqué, but had not read it.

Charamba said the doctors' departure was being held up by ``paperwork'' and ``interface between different government departments.'' He said the country's immigration office still needed to formally advise the Foreign Ministry of the Cubans' travel plans, and the ministry needed to brief the president.

U.S. INTEREST

``As soon as we open our doors on Monday, that communication will happen,'' Charamba said, noting that the country's immigration laws require the Cuban defectors to leave within 14 days. ``Once that is done, they will be free to leave the country.''

He dismissed the American interest in the case.

``If the Americans had an interest in giving asylum to these people they would have done that when they went to the American Embassy seeking asylum,'' Charamba said.

Charamba said the doctors' defection -- which occurred a month after they arrived as part of a contingent of 152 Cuban doctors on a medical assistance mission from Cuba -- caught his government off guard.

``We were expecting doctors, not social dissidents,'' he said. ``We were hoping that they would help Zimbabwe, not the other way around. Unfortunately, they came to Zimbabwe as a stepping stone. That is precisely why we chose to send them back.''

ASYLUM BID

The two doctors sought asylum at the Canadian Embassy on May 24.

The following day, they gave an interview to a local newspaper criticizing Castro, setting off a chain of events that culminated on June 2, when they were taken from their beds and flown to Johannesburg, South Africa, where Cuban diplomats and Zimbabwean security agents tried to force them aboard a Paris-bound Air France flight with a connection to Havana.

Air France crew members refused to board the doctors and South African authorities sent them back to Zimbabwe.

Lyman, the former ambassador, compared the standoff in Zimbabwe to a 1997 case involving a North Korean defector in China who sought asylum in the South Korean Embassy in Beijing. China had backed the North in the Korean war, but in recent years had sought improved economic ties with South Korea.

FACE-SAVING MOVE

After a five-week diplomatic standoff, Chinese officials saved face with both Korean nations by sending defector Hwang Jang Yon to a third country -- the Philippines. He stayed in the Philippines for a month before leaving for South Korea, where he shared some of North Korea's top-secret military plans.

The Western diplomat monitoring the situation in Zimbabwe said the case is being very closely watched because it could spur the defection of other Cuban doctors working in southern Africa.

``It's a very interesting issue of what will happen down the line,'' said the diplomat, noting that Cubans fear the disintegration of one of their prized assistance programs.