Speaking at a news conference wrapping up his visit here, Harkin also called on the U.S. government to adopt more moderate policies toward the communist-run country, promoting more openness between the nations while still emphasizing respect for human rights.
"Some said I should not come here under these circumstances," Harkin told reporters before leaving for his flight home Thursday afternoon. "But a policy of isolation and the embargo of 42 years has not achieved any U.S. objectives nor made life any better for the average Cuban citizen."
Harkin, a Democrat from the farm state of Iowa, was the first American senator to visit Cuba since Fidel Castro's government began its mass roundup of opposition leaders in mid-March.
Iowa Gov. Tom Vilsack announced earlier this month that he had scrapped plans for his own trip to Cuba precisely because of the crackdown.
"That means I'm not going today, tomorrow, or until things improve dramatically for the people of Cuba," Vilsack said at the time.
Cuban prosecutors tried the dissidents in hearings that lasted no more than one day for each. They were sentenced to prison terms ranging from 6 to 28 years.
The crackdown came during a rash of plane and boat hijackings, which ended earlier this month when the government executed by firing squad three men convicted of terrorism in the attempted hijacking of a ferry filled with passengers. No one was harmed in that attempt to commandeer a boat to the United States.
In meetings here with parliament speaker Ricardo Alarcon and Foreign Minister Felipe Perez Roque, "I made it very clear that people on all sides of U.S. policy toward Cuba were united in condemning the arrests and sentences of these 75 people," the senator said.
Harkin said he also met with nine European ambassadors based in Havana, as several leading government opponents who members of his delegation declined to name, evidently at their request.
The senator said the diplomats and the dissidents convinced him "that the best course of action now is moderation, not escalation; engagement, not isolation'' by the American government."
Harkin said did not meet with President Fidel Castro, nor had such a meeting been scheduled. "For whatever reason, it just didn't happen," he said.
The Cuban government, he said, "should grant the appeals of all 75 prisoners of conscience and release them forthwith."
But Harkin said that at the same time, the administration of U.S. President George W. Bush should make it clear to Cuba -- as was stated recently in a television interview by U.S. Defense Secretary Donald H. Rumsfeld -- "that there are no plans for military action against Cuba."
Thirdly, the United States should meet with its allies in Latin America and elsewhere to "review our past policy toward Cuba and chart a new course that does not escalate tension between Cuba and the U.S.," Harkin said.
Harkin has led U.S. congressional efforts in recent years to ease sanctions that prevent most Americans from traveling to and doing business with the Caribbean nation.
A new U.S. policy toward Cuba, he said, should encourage more trade and travel between the two countries, but also "promote more openness and respect for human rights."
By Anita Snow