A search and rescue operation is underway in the Caribbean for two missing sailboats filled with humanitarian supplies travelling from Mexico to Cuba.

Mexico has deployed naval teams and military search aircraft to locate the Friendship and Tigger Moth, which were carrying at least nine crew members, the Mexican navy said in a statement.

The vessels had been expected to arrive in Havana on Tuesday or Wednesday, but there has been no communication from them and no confirmation of their arrival, the navy said.

The Mexican navy said it was committed to using all of the resources at its disposal to locate the boats and ensure the safety of the crews.

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

The nine crew members are from Poland, France, Cuba and the US. Mexico said it has established contact with maritime rescue coordination centres from each country along with their diplomatic representatives.

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.

There has been no comment on the missing boats by the Cuban government.

Earlier in the week, the Cuban government widely celebrated and warmly received another boat that had carried 14 tonnes of humanitarian aid to the island. This vessel, dubbed Granma 2.0, delivered solar panels, medicines, baby formula, bicycles and food amid economic challenges.

Volunteers and NGOs have largely spearheaded efforts to deliver humanitarian aid to Cuba since January, when US President Donald Trump's fuel embargo on the Communist-run country began. The United Nations has warned of dire supply shortages, with over 50,000 surgeries cancelled in Cuba amid electricity supply constraints.

The Cuban nation has relied heavily on Mexico's humanitarian shipments recently, as it struggles through multiple nationwide blackouts under the US energy blockade.

Trump has increased pressure on Cuba since US forces seized former Venezuelan President Nicolás Maduro in January. Venezuela had previously provided large quantities of oil to Cuba, its regional ally.

Last week, Trump mulled the possibility of a friendly takeover of Cuba, later saying it would be an honour. In response, Cuban Deputy Foreign Minister Carlos Fernandez de Cossio insisted that the political system of Cuba is not up for negotiation. Cuban President Miguel Díaz-Canel announced that early stages of US-Cuba negotiations had begun, although their progress remains unclear.