US military aircraft flying in the airspace of Aruba and Curaçao will switch on their transponders, authorities in both countries have said, following agreements with the United States.

Aruba’s prime minister Mike Eman said at a press conference on Wednesday that military exercises in the region have been stepped up and that there is close contact about this with the US, local media reported. Commercial air and maritime traffic will not be affected, Eman said, and will “continue calmly and without problems”.

A transponder is an electronic device that receives signals from air traffic control and automatically sends back a unique identification code and the aircraft’s altitude, making the plane visible on radar and helping to prevent collisions.

There have been at least two near misses in Curacao’s airspace in recent days involving US military aircraft flying without visible transponders. The former Dutch colonies are only a few kilometres from Venezuela.

The US has recently increased its military presence in the Caribbean, moving additional troops and naval vessels into the region. President Donald Trump said on Wednesday that Venezuela is now surrounded by “the largest armada in the history of South America”.

The heightened military activity has already had consequences for tourism. On Wednesday, the cruise ship Norwegian Epic decided not to dock in Curaçao, dropping the island from its itinerary at the last minute.

On Wednesday, NOS said KLM has introduced additional safety measures on flights to and from Curaçao following the near misses. The airline is reported to have strengthened its internal safety procedures and is requiring its aircraft to be as visible as possible while flying in Curaçao’s airspace.

There has so far been no official confirmation of the new arrangements about the use of transponders from the US, broadcaster NOS said.