Tension between the two longtime rivals has spiked since the US attack on Venezuela, which resulted in the deaths of 32 Cuban military and intelligence officers believed to be defending Maduro, marking the first clashes between US and Cuban forces in decades.

Cubans bundled in hats and jackets gathered on the capital`s Malecon waterfront boulevard, waving Cuban and Venezuelan flags under grey skies as blustery winds and waves buffeted the coast.

Cuban President Miguel Diaz-Canel, dressed in olive-green military garb and with his back to the US embassy, called on Cubans to remain united in the face of US pressure.

“No, imperialists, we have absolutely no fear of you…and we don`t like to be threatened,” he said, turning to wave his finger at the embassy building. “You will not intimidate us.”

Both sides have ratcheted up political rhetoric in recent days, marking a new low in long frosty relations between the US and communist-run Cuba, which lies 90 miles from the shores of Florida.

US President Donald Trump said on Sunday that no more Venezuelan oil or money would go to Cuba, warning Havana to make a deal before it’s “too late”.

Diaz-Canel said after Trump’s comments that Cuba would defend its homeland “to the last drop of blood.”