By CHRISTOPHER MARQUIS
 Herald Staff Writer

 WASHINGTON -- Cuba has tentatively accepted two U.S. requests to enhance
 antinarcotics cooperation between the countries, even as leading Republican
 lawmakers portray the nation as a major trafficker, U.S. and Cuban sources said.

 Cuban officials have told U.S. diplomats they are willing to let the Clinton
 administration station an anti-narcotics agent at the U.S. mission in Havana, and
 would be prepared to collaborate on a continuing basis. If final details are worked
 out, the agent would probably be a Coast Guard officer equipped with electronic
 devices to detect drugs in containers.

 Cuba has also agreed to upgrade its communication links with Coast Guard
 officials, allowing for voice contacts between enforcement authorities and a secure
 radio link, the sources said. Currently, Coast Guard officials contact their
 counterparts by fax on a case-by-case basis and use radio frequencies that can
 easily be monitored by traffickers.

 The government of President Fidel Castro has proposed, moreover, that both
 countries meet on a regular basis to discuss antinarcotics operations. But
 administration officials are cool to that idea, saying Havana is seeking to build its
 political legitimacy through routine contacts.

 Administration officials on Wednesday sought to downplay Cuba's agreement just
 seven weeks after they traveled to Havana to ask for the changes. Republican
 lawmakers harshly criticized the visit and have called on the President to halt
 intelligence sharing with Cuba and subject the island to penalties as a major
 trafficking nation.

 An administration official who is monitoring the contacts with Cuba minimized the
 progress Wednesday as part of an ongoing effort.

 ``This is not revolutionary and new,'' he said, after asking not to be named.
 Antidrug cooperation with Cuba, he said, ``is something that has had concrete
 success in the past. This is a way to systematize it in the future.''

 But on Capitol Hill, some Republican lawmakers were swift to condemn any effort
 to upgrade relations. The Cubans are seizing on U.S. concerns over drugs to try
 to open a broader political dialogue, said Marc Thiessen, spokesman for Sen.
 Jesse Helms, chairman of the Foreign Relations Committee.

 ``They see it as a path toward normal relations with the United States and a
 chance to whitewash their drug record,'' Thiessen said.

 Drug-smuggling is the most prominent of several national security concerns
 involving Cuba that have recently pitted the Clinton administration against
 hard-line anti-Castro lawmakers. In recent years, Castro foes have denounced
 Cuba's intermittent construction of a Soviet-style nuclear power plant, the
 potential for mischief by its biotech industry and the Soviet eavesdropping post at
 Lourdes.

 The administration has long maintained that it benefits from antinarcotics
 cooperation with Havana. Drug czar Barry McCaffrey recently said there is ``no
 conclusive evidence to indicate that the Cuban leadership is currently involved in
 this criminal activity.'' U.S. officials praise Cuban cooperation for netting nearly
 eight tons of cocaine aboard a Honduran freighter in 1996.

 But anti-Castro Republicans point to a seizure in Colombia last December of 7
 1/2 tons of cocaine bound for Cuba through a Spanish-Cuban firm. Rep. Benjamin
 Gilman, chairman of the International Relations Committee, has demanded an
 investigation into the incident and asked that Secretary of State Madeleine
 Albright list Cuba as a nation subject to an annual process certifying that it is
 combating drugs in good faith.