Edward Snowden will take the Norwegian state to court in a bid to secure a free passage there, a Norwegian law firm representing the former US spy contractor said on Thursday.
Snowden has been invited to Norway to receive a freedom of speech award from the local branch of writers' group PEN International, but is worried that he would be handed over to the United States, his lawyers say.
"The purpose is to get legally established that Norway has no right to extradite Snowden to the US," the law firm, Schjoedt, said in a statement.
"US authorities have already asked that Snowden will be extradited to the US if he was to arrive in Norway," Hallvard Helle, the lawyer representing Snowden, told Reuters.
"It is a case they (the Norwegian authorities) have not wished to comment on previously, so therefore we want a legal clarification of this," Helle said, when asked whether Norway had said it would extradite Snowden if he entered the country.
The Norwegian Justice Ministry said: "The ministry does not wish to comment on a case that potentially will be handled and decided by the court."
Norway, a member of the NATO military alliance, has very close diplomatic ties with the United States, but the judiciary can defy the government.
A court ruled on Wednesday that Norway had violated the human rights of mass murderer Anders Behring Breivik by keeping him in isolation since he was sentenced in 2012 for killing 77 people.
Snowden, whose supporters say he boldly exposed government infringements of privacy, fled the United States in May 2013 and now lives in Russia where he was granted asylum. The US government filed espionage charges against him for leaking intelligence information.
Snowden is among the top tips for this year's Nobel Peace Prize, an award picked by a Norwegian committee and awarded in Oslo.
Norway and Russia share a border making it possible to travel by land.