Miami-based Carnival Cruise Line on Thursday became the first U.S. company sued for using property confiscated six decades ago by Cuba’s revolutionary government, after the Trump administration ended a waiver of the law permitting such lawsuits.

The actions, in federal court in Miami, were filed by two U.S. citizens whose parents owned commercial docks in Havana and in the southeastern Cuban city of Santiago. “The communist government,” the claim said, “nationalized, expropriated, and seized ownership and control” of the properties when their families fled the island in 1960.

The claims, potentially worth tens of millions of dollars or more, were made under a 1996 sanctions law against Cuba that prohibited “trafficking” in expropriated property. Every administration since then had waived the provision on national security grounds, but the Trump administration announced last month it would no longer do so.

“Effective May 2 . . . Americans will finally have a chance at justice,” Secretary of State Mike Pompeo said at the time in a Twitter post.

Carnival has operated cruises to Cuba since 2016, when the Obama administration sought to normalize relations. Although the Trump administration has systematically rolled back the Obama openings, among other moves restricting U.S. citizen travel and remittances by Cuban Americans to relatives on the island, its efforts to cripple the Cuban economy have intensified along with accusations that Cuba is the main prop holding up the Venezuelan government of Nicolás Maduro.

Roger Frizzell, Carnival’s senior vice president and chief communications officer, said in a statement that the company was “continuing with our normal cruise schedule to Cuba.”

The Cruise Lines International Association, an industry group. said that travel to Cuba “falls under the lawful travel exemption under Title III of the Helms-Burton Act,” the 1996 law. “Our cruise members have been and are now engaged in lawful travel to Cuba as expressly authorized by the U.S. federal government.”

Some companies and their lawyers maintain that certain activities, including the use of properties “necessary” for lawful travel, are explicitly exempted from the law, even without a waiver.

“We have a different interpretation” than the cruise industry, said Rodney G. Margol, the Florida-based attorney for both plaintiffs in the case filed Thursday. Margol said that Carnival is only one company potentially liable and that his clients “are entitled to pursue their claims under law against each and every trafficker” of the confiscated property.

But the trafficking provision, barred from implementation until now, has never been interpreted by U.S. courts. The Trump administration has said that it not only covers U.S. companies and entities but is also applicable worldwide. It also denies visas to any individuals associated with such “trafficking.”

European and Canadian companies with extensive investments in Cuba are likely to reject and take counteraction against any attempt to hold them liable under the law.

Although they have been prohibited until now from reaching court, nearly 6,000 claims, with a value of approximately $2 billion — as much as $8 billion with applicable interest — have already been certified as actionable by the Foreign Claims Settlement Commission, an independent agency within the Justice Department.

“The most recent estimate we have from 1996, at the time that the law was enacted, [is] that there could be up to 200,000 uncertified claims . . . and that value could very easily be in the tens of billions of dollars,” Kimberly Breier, assistant secretary of state for Western Hemisphere affairs, told reporters last month.

In a news conference outside the U.S. District Court for the Southern District of Florida in Miami on Thursday, Mickael Behn said that his family’s property, now incorporated in Delaware as the Havana Docks Corp., was stolen from his grandfather “at gunpoint” by the revolutionary government in 1960.

Carnival, he said, “knew very well the ownership” of the docks in the Cuban capital when they began operating there. “It wasn’t a secret to them or to anyone else,” he said. Choking up as he read a statement, Behn said that “we can finally get justice after 60 years, from those who stole our property and those who have been using our ports for their own business purposes.”

The other plaintiff who sued Thursday, Jacksonville neurosurgeon Javier Garcia-Bengochea, said his family’s waterfront property in the Port of Santiago had been seized in 1960.

“For the first time in 59 years,” he said at the news conference, “an American victim of theft by the Castro regime can legitimately stand before you publicly and assert their property rights and seek damages [from] those who are using these stolen properties.”