Two British cruise ships that visited the Falkland Islands were refused entry to an Argentinian port today, amid tension over the disputed archipelago.

The Adonia, owned by P&O cruises and registered in London, and the Princess Cruises vessel Star Princess, registered in Hamilton, were both blocked from entering Ushuaia in southern Argentina after both ships stopped at the Falklands on Saturday.

"We are very concerned to hear the Adonia and Star Princess have been refused access to the port of Ushuaia," said a spokesman for Britain's Foreign Office.

"There can be no justification for interference in free and legitimate commerce.

"British diplomats in Argentina are urgently seeking to clarify the circumstances surrounding this incident, and we are in contact with the company concerned."

Tensions are running high between Britain and Argentina over the Falklands, which London controls but Buenos Aires claims, ahead of the 30th anniversary in April of the start of the war between the two nations over the islands.

Argentina has also reacted angrily to the deployment of Prince William to the Falklands as part of his job as a Royal Air Force search and rescue pilot, and to a planned fact-finding trip by British lawmakers next month.

Carnival UK, which owns both P&O and Princess Cruises, said in a statement the Adonia was now sailing towards Punta Arenas in Chile, its next port of call on an 87-night tour of South America.

The Star Princess was on a 14-night South America cruise which started in Rio de Janeiro on February 18.