A new film shows Edward Snowden has been joined by his American girlfriend in Russia.

A near two-hour documentary paints an intimate portrait of Snowden holed up in a Hong Kong hotel as he blows the whistle on National Security Agency dealings and then plots his escape.

The film says in July, Snowden's long-time partner Lindsay Mills joined him in Moscow, where he was granted asylum after revealing the extent of US government surveillance.

A short segment shows her preparing dinner with Snowden in a wood-panelled kitchen, but the couple's conversation is not recorded and she is not interviewed.

He says he feels "badly" about simply disappearing while she was on vacation but said he did it to protect her.