HAVANA, Cuba (AFP) — Communist-run Cuba enacted new constitution Wednesday that recognises the role of the free market in the country’s future while championing socialism as Havana faces increasing US pressure.

The National Assembly met in extraordinary session to enact the new constitution, ratified in a February referendum after months of public debates.

“Today our constitution is proclaimed. Our duty is only to it and to Cuba,” President Miguel Diaz-Canel said in a tweet.

In a rare speech, Communist Party chief Raul Castro told the assembly the new constitution “is the daughter of its time and reflects the diversity of society. It becomes a legacy for new generations of Cubans.”

The new document, which replaces a Cold War-era text, recognises a limited role for the free market, private ownership and foreign investment as being necessary to grow a US sanctions-bound economy riddled with shortages.

Castro, who stood down as president in April 2018 in favour of Diaz-Canel, warned of tough times ahead for the nation.

“We need to be alert and aware that we face additional difficulties and that the situation could worsen in the coming months,” he said.

The new constitution formally recognizes changes that have already become part of daily economic life on the Caribbean island.

Cubans have been allowed to work for themselves or in privately-owned businesses since 2008, in a sector which now employs 591,000 people — 13 per cent of the workforce.

But the political content of the constitution remains largely unchanged from the 1976 version it replaces, reaffirming the central role of the Communist Party and the “irrevocable” nature of socialism.

Little has changed either in the relationship with Cuba’s nemesis across the Florida Straits, after US President Donald Trump reversed a thaw introduced under the previous administration of Barack Obama.

Trump has branded Cuba as being part of the “Troika of Tyranny” with its leftist allies Venezuela and Nicaragua and pledged to increase pressure on the country over its support for Venezuela’s embattled President Nicolas Maduro.

Last week, US sanctions targeted vital Venezuelan oil shipments to Cuba.

“The tone of the United States has become more and more aggressive, but we will not give up any of our principles,” Castro told lawmakers.

“We have informed the US administration that Cuba is not afraid and will continue to build the future of the nation without foreign interference,” he said.

The US has threatened to revive the dormant 1996 Helms-Burton Act that permits Cuban exiles to pursue claims against companies that profit from assets nationalized after the 1959 Cuban revolution.

Washington has also cancelled a historic agreement allowing Cuban baseball players to play in the lucrative US leagues without having to defect, and threatens to include the island on a list of countries supporting terrorism

US Secretary of State Mike Pompeo said when the referendum was held in February that “no one should be fooled” by the exercise “which achieves little beyond perpetuating the pretext for (the) regime’s one-party dictatorship.”

The promulgation of the new constitution comes 150 years to the day since the island’s first set of governing principles were adopted by the independence movement against Spain on April 10, 1869.