A search effort is underway in the Caribbean after two sailboats transporting humanitarian supplies from Mexico to Cuba failed to reach their destination, Mexican authorities said.

The Mexican navy confirmed it has dispatched naval units and military aircraft to locate the vessels, identified as the Friendship and Tigger Moth, which were carrying at least nine people.

According to officials, the boats were scheduled to arrive in Havana earlier this week, but neither has made contact nor been confirmed to have docked.

In a statement, the navy said it is mobilizing all available resources in the ongoing operation, with the priority of locating the missing vessels and ensuring the safety of those on board.

The sailboats departed Isla Mujeres, in the Mexican state of Quintana Roo, on 20 March.

Crew members aboard the vessels are nationals of Poland, France, Cuba and the United States. Mexican officials said coordination has been established with maritime rescue centers and diplomatic representatives from each of those countries.

"The captains and crews are experienced sailors, and both vessels are equipped with appropriate safety systems and signalling equipment," the convoy's spokesperson said in a statement to Reuters.

"We are co-operating fully with the authorities and remain confident in the crews' ability to reach Havana safely."

Cuban authorities have not issued any public comment regarding the missing boats.

Earlier this week, a separate aid vessel arrived in Havana carrying 14 tonnes of supplies and was welcomed by officials.

The ship, named “Granma 2.0” in reference to the vessel used by Fidel Castro during the Cuban Revolution, delivered items including solar panels, medicines, baby formula, bicycles and food.

Since January, humanitarian shipments to Cuba have largely been organized by volunteer groups and non-governmental organizations, following the imposition of a U.S. fuel embargo under President Donald Trump.

The United Nations has warned that the country is facing severe shortages, with more than 50,000 surgeries reportedly cancelled due to ongoing electricity disruptions.

In recent weeks, Cuba has increasingly depended on shipments from Mexico as it grapples with repeated nationwide blackouts linked to the U.S. energy restrictions.

Pressure on Cuba has intensified after U.S. forces detained former Venezuelan President Nicolás Maduro in January. Venezuela had been a key oil supplier to the island.

Last week, Trump raised the possibility of a "friendly takeover" of Cuba, later describing such a move as an "honour". Cuban Deputy Foreign Minister Carlos Fernandez de Cossio rejected the suggestion, stating that "the political system of Cuba is not up for negotiation".

Cuban President Miguel Díaz-Canel has said that preliminary discussions between the United States and Cuba are under way, though details on their progress remain unclear.