By Lesley Wroughton and Matt Spetalnick
WASHINGTON (Reuters) - The Trump administration is lifting a long-standing ban against U.S. citizens filing lawsuits against foreign companies that use properties seized by Cuba’s Communist government since Fidel Castro’s 1959 revolution, Secretary of State Mike Pompeo said on Wednesday.
The major policy shift, which the State Department said could draw hundreds of thousands of legal claims worth tens of billion of dollars, appears intended to intensify pressure on Havana at a time Washington is demanding that it end its support for Venezuela's socialist president, Nicolas Maduro.
U.S. President Donald Trump's decision, which will take effect on May 2, is strongly opposed by the European Union, whose companies have large business interests on the island.
"Any person or company doing business in Cuba should heed this announcement," Pompeo said at a news conference.
"Cuba’s behaviour in the Western Hemisphere undermines the security and stability of countries throughout the region, which directly threatens United States national security interests," he said.
Trump's national security adviser, John Bolton, will discuss on Wednesday the administration's decision in a speech in Miami and announce new sanctions on Cuba, Venezuela and Nicaragua, countries he has branded a "troika of tyranny," a senior U.S. official said, speaking on condition of anonymity.
It was unclear, however, whether such property claims will be acceptable in U.S. courts. The European Union has already warned it could lodge a challenge with the World Trade Organization.
Trump decided to allow a law that has been suspended since its creation in 1996 to be fully activated, permitting Cuban-Americans and other U.S. citizens to sue foreign companies doing business in Cuba over property seized in decades past by the Cuban government.
Title III of the Helms-Burton Act had been fully waived by every president over the past 23 years due to opposition from the international community and fears it could create chaos in the U.S. court system with a flood of lawsuits.
The move, which could deal a blow to the Cuban government's efforts to attract foreign investment, marks a further step by Trump to roll back parts of the historic opening to Cuba, an old Cold War foe, under his predecessor, Barack Obama.
Kim Breier, assistant secretary of state for Western Hemisphere affairs, said the administration had been in close contact with allies in Europe and elsewhere before the Cuba decision and that a number of European firms operating there will not have any concerns.
She said, however, that a U.S. government commission has certified nearly 6,000 claims for property confiscated in Cuba with a current value, including interest, of about $8 billion (£6 billion).
"There could be up to 200,000 uncertified claims … and that value could very easily be in the tens of billions of dollars," she added. "It will depend on whether claimants decide to pursue legal cases or not.”
(Additional reporting by Makini Brice and Doina Chiacu; Editing by Meredith Mazzilli)