Meanwhile Mr Snowden’s father, Lon, is applying for a visa to visit him in Russia.
His whereabouts are not publicly known after he left Moscow’s international airport last week, but he is understood to have now registered an address in Russian territory.
Mr Snowden had spent more than five weeks at the airport while trying to find a country to take him in.
His father’s lawyer, Mattie Fein, said: “We do not have a set date yet but we have been working closely with Anatoly Kucherena, Ed Snowden’s attorney, on setting a definitive date which will be sometime in August.”