BRITAIN is "violating" Wikileaks founder Julian Assange's human rights by refusing to let him leave London, Ecuador's President Rafael Correa said yesterday.

Speaking during a visit to Paris, Correa said Assange's future was "in Britain's hands" as the Australian-born activist marks almost a year-and-a-half spent holed up in the Ecuadoran embassy in London.

"If (they) want to keep him there for 30 years, he'll stay there 30 years, but that would violate his human rights," Correa said.

Correa maintained that the offer of asylum he first made to Assange in August 2012 remained open, and added that he had the right "to demand asylum in the country of his choice".

Assange, who oversaw WikiLeaks' publication of a huge trove of classified US military and diplomatic documents, took refuge in the Ecuadoran embassy in London July 17, 2012 to escape extradition to Sweden.

He is wanted for questioning by Swedish authorities about allegations of sexual assault brought separately by two women.

Correa suggested Assange could answer prosecutors' questions by video link, and said he believed "the case would then be closed".

Ecuador has threatened to sue Britain in an unspecified international court over the status of Julian Assange if it rejects a proposal to submit the matter to a bilateral commission.

The 42-year-old Assange also fears any future extradition to the United States were he to leave the Ecuadoran embassy, as he could face the death penalty there for leaking the confidential diplomatic cables.

His case mirrors that of Edward Snowden, the US intelligence leaker who has been granted asylum in Russia although he is wanted in the US on espionage charges.

In Paris for talks with his French counterpart Francois Hollande, Correa also touched on his country's ongoing legal battle with American petrol giant Chevron, which is attempting to avoid paying a record fine for pollution.

A court in Ecuador ordered Chevron to pay $US9 billion ($9.5 billion) in damages to indigenous people from Lago Agrio in the Amazon for environmental damage.

But the firm referred the case to an arbitration panel in The Hague and won its case in September with a ruling that Chevron was protected from collective action claims.

"It's a travesty of justice," Correa said.

Chevron is also alleging fraud and violations by the villagers and their American lawyer under the Racketeer Influenced and Corrupt Organizations Act (RICA), designed for use in mafia cases, in an ongoing case in a New York court.

Correa and Hollande signed a strategic agreement on Thursday designed to further co-operation in the areas of university research and technology.