In a joint move, Brazil, Mexico, and Spain have pledged to scale up aid to Cuba to ease a humanitarian crisis they say stems from a United States blockade of the island.

Citing the US action in a joint statement published late on Saturday, the three governments urged dialogue, cautioned against any military intervention in Cuba, and said Cubans must decide their own future.

US President Donald Trump has repeatedly threatened to invade Cuba and imposed an oil blockade on the island.

Following the Feb 28 launch of the military strikes on Iran, Trump also floated the idea of "taking" Cuba, which has meanwhile suffered widespread blackouts that officials blame on the US blockade.

The announcement followed Spain's Prime Minister Pedro Sanchez hosting Brazil's President Luiz Inacio Lula da Silva and Mexico's President Claudia Sheinbaum in Barcelona for a gathering of leftist leaders on the weekend.

The summit aimed to defend multilateralism and democracy amid a growing challenge from the far right.

Also present were South Africa's President Cyril Ramaphosa, Colombia's President Gustavo Petro, and Germany's Vice-Chancellor Lars Klingbeil, among others.

At the opening of the gathering titled IV Meeting in Defense of Democracy in Spain's second-largest city, Sanchez said: "Democracy cannot be taken for granted."

A prominent progressive on the world stage, Sanchez has been among the fiercest critics of the US-Israeli strikes on Iran.

Sanchez refused to allow the US to use Spanish bases for military operations against Iran, drawing Trump's ire. The US president has also castigated the Spanish leader for rejecting an increase in defense spending from 2 percent to 5 percent of GDP.

The gathering of leftist leaders comes amid the US president's persistent criticism of global institutions, notably the United Nations and NATO, and his decision to wage war against Iran.

"We all see the attacks against the multilateral system, the repeated attempts to undermine international law and the dangerous normalization of the use of force," Sanchez said.

Spain's premier also took aim at the global far right, saying it "screams and shouts not because they are winning but because they know their time is running out".

He added that "their vision of how the world should be ordered is falling apart because of tariffs and wars", and called "their embrace of climate change denial, xenophobia, and sexism" their "greatest error".

Sanchez, Lula, Ramaphosa, and Klingbeil, who also serves as Germany's finance minister, remained for the day's second event, the inaugural Global Progressive Mobilization.

"The far right is international, so we must be too," Klingbeil told a crowd of left-wing activists, academics, and policymakers.

jonathan@mail.chinadailyuk.com