US television network CNN says the US military has been sharply increasing intelligence-gathering flights around Cuba.

CNN reported on Sunday the results of its analysis of publicly available aviation data.

It says the US Navy and US Air Force have carried out at least 25 reconnaissance flights off the coast of Cuba since February 4, using patrol planes and drones.

The report says most of the flights took place near the capital Havana and the eastern city of Santiago de Cuba, with some coming within about 60 kilometers of the coast.

CNN says the US military flew only a handful of surveillance aircraft near Cuba last year.

The US administration is ratcheting up pressure on Cuba with economic sanctions. President Donald Trump has hinted at taking steps against the Caribbean nation once its military operations in Iran end.

CNN says that before US forces launched military campaigns against both Venezuela and Iran, the number of surveillance flights increased near the two countries.

The news outlet says the move “is likely to be unsettling” for Cuban officials.