Cuba detained 140 political prisoners in January - U.S. official
"The nature of the Cuban regime has not changed and we have not claimed so," Tom Malinowski, the State Department's top human rights official, told a congressional hearing discussing the Obama administration's new policy towards Cuba.
Malinowski said, however, the number of detentions had fallen.
"We have seen a significant decrease in the number of arrests but I don't want to say that one month represents a trend," he said.
(Reporting by Lesley Wroughton and Patricia Zengerle; Editing by Bill Trott)