Oslo (AFP) - A court in Norway on Monday refused to provide assurances to US intelligence contractor Edward Snowden that he would not be extradited if he visits the country to accept an award in November.

Snowden, who has been living in exile in Russia since 2013 after revealing widespread US foreign surveillance, filed a civil lawsuit against the Norwegian justice ministry in April to prevent it, in advance, from acting on any extradition request.

The Norwegian branch of the PEN Club has invited Snowden to collect the Ossietzky prize for freedom of expression on November 18.

But Snowden fears he will be extradited to the United States if he travels to Norway.

The Oslo court rejected his request, upholding the justice ministry's argument that the basis for an extradition cannot be evaluated until an extradition request is actually submitted.

In practice, that means Norway could only decide whether to extradite Snowden to the US once Washington had asked Oslo to extradite him.

The 33-year-old American was charged by US authorities with espionage and the theft of state secrets after revealing the extent of surveillance programmes run by the National Security Agency.

Norway was one of the countries where Snowden had sought asylum when he fled the US, but Oslo's response was that asylum seekers had to be physically present in the country to apply.

Considered a whistleblower by some and a traitor by others, Snowden won a similar Norwegian award in 2015, but was unable to collect it in person for the same reasons.

Snowden has also been nominated for the Nobel Peace Prize, also awarded in Norway, for a third straight year. This year's award will be announced on October 7.