Falkland islanders have voted overwhelmingly in favour of remaining a British overseas territory in a referendum designed to send a strong message to Argentina, which earlier derided the poll as illegal.

About 92 percent of the islands' 1,672 eligible voters turned out to deliver a 98.8 percent "yes" vote in favour of staying a self-governing British territory, election officials in capital Port Stanley announced on Tuesday.

Only three votes were cast against the islands remaining British.

The resounding "yes" result, delivered at around 22:30pm local time (01:30 GMT) on the remote South Atlantic territory, was setting the stage for an after-vote party.

Argentina, which invaded the islands in 1982 before its troops were removed by a British task force after a short but bloody war, maintained its dismissive line on the vote.

"It's a manoeuvre with no legal value, which has neither been convened nor supervised by the United Nations," Alicia Castro, Argentina's ambassador to London, said.

"We respect their way of life, their identity. We respect that they want to continue being British, but the territory they inhabit is not British."