VANESSA ARRINGTON
Associated Press

HAVANA - Cuban academics hoping to attend a gathering of Latin America experts in Puerto Rico were denied visas by the American government, marking the latest in the current U.S. administration's trend of shutting out Cubans.

Some 55 philosophers, economists, and historians were told last week they'd be unable to travel to this month's Latin American Studies Association congress in San Juan. Visa requests for four academics were still pending, said Sheryl Lutjens, an American political science professor at Northern Arizona University.

"These people represent strong scholars who think critically and who are often experts in their area where there are no others," said Lutjens, who co-chairs the association's Cuba section and is currently visiting the country. "This is alarming."

Academic exchange between Cuba and the United States has diminished over the last two years since the administration of President Bush started tightening long-standing trade and travel regulations against the island's communist government.

The "Cubans not welcome" message has reached new and broader extremes in recent months. The U.S. government provoked outrage after denying Cuba participation in this month's World Baseball Classic - a decision that was later reversed. U.S. officials also pressured a major U.S.-owned hotel in Mexico City to kick out 16 Cuban officials attending a meeting with U.S. oil executives in February.

Fewer American scholars are traveling to Cuba, too, wary of complicated U.S. rules that can lead to hefty fines and punishment if broken.

"They have been dissuaded by the new regulations," Lutjens said of other professors and researchers. "People are, I think, confused and perhaps even frightened by the thought that they might be doing something that's not permitted."

Milagros Martinez, a Cuban political scientist at the University of Havana, said about 30 American scholars used to be conducting research in Cuba each month, but now it's down to about two per month.

The Latin American Studies Association, known as LASA, is the largest professional grouping bringing together people and institutions to study the region. Its international congress, held every 18 months, is the world's leading forum for academic discussion on Latin America and the Caribbean. The association has more than 5,000 members.

Nearly 100 Cubans attended the LASA congress in Miami in 2000; more than 80 attended in 2001 in Washington and 67 attended in 2003 in Dallas. None attended the October 2004 congress in Las Vegas, where U.S. visas were denied for more than 60 scholars.

Lutjens said that in its rejection of the latest Cuban requests, the United States cited Section 212f of U.S. Immigration and Naturalization Law, which states that the American president can prohibit entry to foreigners when their visits are deemed "detrimental to the interests of the United States."

U.S. officials in Havana have not made any statements about the latest denials, and generally cite a policy prohibiting comment on individual visa cases.