Britain said on Thursday it supported the rights of Falkland islanders to exploit their oil reserves after Argentina said it would take legal action against companies involved in energy exploration around the South Atlantic islands.

Hydrocarbon exploration is a legitimate commercial venture and the British government supports the rights of the Falkland islanders to develop their hydrocarbons sector, a spokesman for Britain's Foreign Office said.

This right is an integral part of the right of self-determination, which is expressly contained in the International Covenant on Civil and Political Rights, he added, referring to a United Nations' treaty.

Argentina and Britain went to war 30 years ago over the disputed islands.

We want to have a full and friendly relationship with Argentina, as neighbours in the South Atlantic, but we will not negotiate away the human and political rights of the Falkland Islands' people, the Foreign Office spokesman said.

He said there could be no negotiations on the sovereignty of the Falkland Islands unless the 3,000 islanders wanted them.

(Reporting by Adrian Croft; Editing by Tim Castle)