Havana, Cuba - Two Mexican navy ships carrying more than 800 tons of crucial humanitarian aid arrived in Cuba on Thursday, defying a brutal US trade embargo that has effectively blockaded oil deliveries.

The shipment arrived weeks after President Donald Trump vowed to starve Cuba of oil after the abduction of Venezuelan President Nicolás Maduro effectively severed the island nation from its main supplier.

Mexican President Claudia Sheinbaum responded to the severance of Cuba's oil supply by initially beefing up her country's supply of the commodity but was quickly blocked by the US embargo.

Trump in late January signed an executive order threatening to impose punishing tariffs on any country that supplies crude oil to Cuba, a decision that Sheinbaum warned could lead to a major humanitarian crisis.

Earlier this week, Sheinbaum's government sent the ships Papaloapan and Isla Holbox on their way to Cuba, packed with more than 800 tons of humanitarian supplies. They entered Havana Harbor on Thursday, AFP reports.

Included among the supplies were fresh and powdered milk, meat, cookies, beans, rice, and personal hygiene items, the Mexican foreign ministry said.

"Mexico has always been in solidarity with Cuba," 52-year-old Cuban national Marila Garcia told AFP at Havana's Malecon waterfront, from where the arriving ships were visible.

Despite the arrival of vitally needed aid, Havana is still struggling from a severe shortage of oil, a problem that Mexico is also keen to remedy.

Emergency measures kicked in this week to conserve the island's dwindling supply. The government shuttered universities, reduced school hours and the workweek, slashed public transport, and cut hospital staffing.

On Monday, Sheinbaum said Trump's "unfair" measures would "strangle" an already teetering economy.

"We will continue supporting them and taking all necessary diplomatic actions to restore oil shipments," she vowed.