Russia's space state agency Roscosmos said on Thursday that a cross-flight programme with NASA to the International Space Station (ISS) had been extended until 2025, Interfax news agency reported.

The cross-flights were extended "in order to maintain the reliability of the ISS operation" and will be carried out on Russian and U.S. spacecraft, Roscosmos said.

The cross-flights involve sending one American astronaut to the ISS as part of the crew of a Russian spacecraft, and vice versa - one Russian cosmonaut as part of an American crew, Interfax reported. (Reporting by Reuters; editing by Guy Faulconbridge)