They warn that European Union and Canadian laws allow counter-claims against any USA lawsuits "so the US decision to allow suits against foreign companies can only lead to an unnecessary spiral of legal actions".
"European companies that are operating in Cuba will have nothing to worry about if they are not operating on property that was stolen from Americans post-revolution", Assistant Secretary for Western Hemisphere Kimberly Breier told reporters.
Canada and the European Union hit back Wednesday at the Trump administration's decision to allow lawsuits against foreign companies connected to properties seized from American firms during the Cuban revolution, vowing to protect their businesses.
The European Union "will be obliged to use all means at its disposal, including in cooperation with other worldwide partners, to protect its interests", said the official letter seen by AFP by EU foreign policy chief Mogherini and trade commissioner Malmstrom.
There have been years of waivers for a provision in a 1996 domestic law of the US, known as the Helms-Burton Act, that safeguarded foreign companies from USA lawsuits.
The latest sally against the Communist regime once headed by Fidel then Raul Castro is being launched in Miami by national security advisor John Bolton. The speech at the Bay of Pigs Veterans Association is to be delivered on the 58th anniversary of the failed U.S. invasion of the island in 1961, an attempt to overthrow the Cuban government. "The world has told John Bolton and the USA government to eliminate the criminal blockade against Cuba and the Helms-Burton Act".
But the official could "not give an assessment on how many companies that applies to".
Countries with large investments in Cuba have ferociously protested the law and threatened to sue in the WTO if Washington tries to interfere with the business ties between Cuba and another sovereign nation. "I personally consider it immoral".
United States airlines and cruise lines that carry hundreds of thousands of travellers to Cuba each year appear to be exempt from the key provision of the Helms-Burton Act.
Every U.S. president since Bill Clinton has suspended the key clause to avoid those trade clashes and a potential mass of lawsuits that would prevent any future settlement with Cuba over nationalized properties. Those could include new sanctions against senior Cuban officials or restrictions on USA trade with or remittances to Cuba, with Breier saying, "You're going to see quite a bit more from us, and this is the beginning of a new process on this".
Foreign investment in Cuba increased slightly in recent years, but it remains far below the levels needed to recapitalize the island's dilapidated, often collapsing infrastructure. The Trump administration's decision is not expected to drive out major foreign players like Pernod-Ricard of France, which makes Havana Club rum, or Spanish hotel chains Melia or Iberostar, but it could prove a major obstacle to new investment from foreign companies.
"It will harm prospective investment in Cuba".
Peters said he also believed the new measure could hurt the Trump administration's effort to force Maduro from power with help from allies like Spain.
The U.S. official said the administration also plans to start enforcing the section of the act that allows the U.S.to deny entry visas to Cubans and citizens of other countries involved in trafficking in the confiscated property.