Cuba has told the United States it will return an American couple who fled to the Caribbean nation after removing their two sons from the care of their grandmother in Florida.

The Foreign Ministry said in a statement it had informed the US Interests Section in Havana -- which functions as an embassy in the absence of full diplomatic ties -- that it would deliver to US authorities Americans Joshua Hakken, his wife Sharyn Patricia and their sons, aged two and four.

On Monday, the Foreign Ministry had told US authorities the four Americans arrived in Havana on the yacht Salty Paw.

Officials in Florida have been searching for Joshua Hakken since Wednesday when he allegedly broke into his mother-in-law's house near Tampa, tied her up and fled with his young boys.

The sheriff's office in Hillsborough County, Florida said Hakken lost custody of the children after being arrested in Louisiana on drug charges in June 2012, following what police described as "an anti-government rally."