Lithuania must block a deal between the European Union and Cuba because island's the communist rulers are using it to legitimise repression, US Secretary of State Mike Pompeo said on Friday. Staunch US ally Lithuania is the only EU state yet to approve the deal - the government said it was prepared to ratify but the right-wing opposition is strongly opposed.

The EU and Cuba signed the Political Dialogue and Cooperation Agreement (PDCA) in 2016 but it will not be fully applied until it is ratified by all EU members.

"We are grateful to Lithuania for not ratifying the agreement and ask that you continue to vote against it, as a symbol of your support for the Cuban people," Pompeo told Lithuanian Prime Minister Saulius Skvernelis in a letter seen by AFP.