Nine Cuban migrants have died and 18 others were rescued after their boat was found off the coast of Florida.

The vessel was spotted by a Royal Caribbean's Brilliance of the Seas cruise ship, according to the US Coast Guard.

The surviving migrants said they had been at sea for 22 days and reported that nine others had died.

They were suffering from severe dehydration when they were rescued off Marco Island, south-west Florida.

"Our deepest condolences to the families of the nine people who recently did lose their lives," said Coast Guard captain Mark Gordon.

"Unfortunately, tragedy is all too common when taking to the sea in homemade vessels with no safety or navigation equipment."

The cruise ship took the survivors to its next port of call, the Mexican island of Cozumel.

Mexican immigration officials were seen helping the exhausted Cubans ashore.

The deaths of the migrants come as Barack Obama makes a historic visit to Cuba - the first trip to the Communist-ruled country by a US president in 88 years.

Mr Obama and Cuban President Raul Castro agreed in December 2014 to end a decades-long estrangement between the two nations.

But the improving relations have led to a surge in migrants from Cuba trying to get the US amid fears preferential asylum rights for Cubans may soon end.