Provincial authorities in Argentina stopped a cruise ship flying under the Bermudan flag from docking in Tierra del Fuego on Monday, upping the ante in Argentina's spat with Britain over the Falklands.

Britain and Argentina fought a 10-week war over the Falkland Islands in 1982 after Argentina invaded the South Atlantic archipelago. The conflict claimed 900 lives.

Tensions have risen before the 30th anniversary of the war this year, and oil exploration by British companies off the islands has raised the stakes.

The Star Princess was prohibited from docking in the southern Argentine port of Ushuaia, capital of Tierra del Fuego province, because Bermuda is an overseas territory of Britain, Argentina's state news agency Telam said on Monday.

The government of the province of Tierra del Fuego prohibited a cruise ship under the flag of a British colony from entering the port of Ushuaia, citing a provincial law linked to Argentina's complaint over the sovereignty of the Malvinas Islands (as the archipelago is known in Argentina), Telam said.

The luxury cruise liner, which has a capacity of 2,600 passengers, had made a stop at Port Stanley in the Falklands before heading to Ushuaia, according to media reports. It had docked in Ushuaia as part of earlier cruises, before the recent increase in diplomatic tensions, Telam said.

London has refused to start talks on the sovereignty of the Falklands unless the 3,000 residents of the islands want them.

Britain hopes to share in any Falkland Islands windfall when oil starts flowing there later this decade.

Sea Lion, a field discovered in 2010 north of the islands by British explorer Rockhopper, will generate $10.5 billion (6.6 billion pounds) of tax and royalty revenues for the Falklands over its estimated 20-year life, Edison Investment Research said this month.

That windfall could swell to $167 billion over the years, Edison analysts said, if four wells being drilled this year off the southern coast and targeting 8 billion barrels of oil resources come in as hoped.

Prince William, second-in-line to the British throne, arrived in the Falklands early this month for a six-week tour of duty as a Royal Air Force search-and-rescue pilot. Argentine President Cristina Fernandez criticized the posting and accused Britain of militarizing the South Atlantic.

A top British diplomat later warned Argentina that Britain would robustly defend the Falklands if necessary, but added that his country remained open to talks with Buenos Aires on any issue except the islands' sovereignty.

British Prime Minister David Cameron has vowed to defend the islands properly.

(Additional reporting By Jorge Otaola; Editing by Paul Simao)