MOSCOW, January 22. /TASS/. The US denial of an entry visa to Russian cosmonaut Nikolay Chub creates a dangerous precedent for cooperation on the International Space Station (ISS), General Director of the Roscosmos space agency Dmitry Rogozin said.

"What the US authorities have done with the entry visa of our cosmonaut is a dangerous precedent for cooperation on the International Space Station," he wrote on his Telegram channel.

Earlier, a source familiar with the situation told TASS that without any explanation, the US refused to issue an entry visa to Roscosmos cosmonaut Nikolay Chub who was supposed to undergo training in the US. The Roscosmos CEO later confirmed this information specifying that he asked NASA to clarify their position on the matter.

Training of foreign astronauts at Russia’s Yury Gagarin Cosmonaut Training Center and of Russian cosmonauts at the Johnson Space Center is a routine practice, giving space crews knowledge of the US and Russian segments of the International Space Station. Such training sessions are held regardless of what kind of spacecraft will be used to deliver cosmonauts and astronauts to the orbit.

Nikolay Chub is a member of the backup crew of ISS Expedition 68, which is to fly to the orbital outpost aboard the Soyuz MS-22 spacecraft in September 2022. He is also a member of Expedition 69’s main crew, to be delivered to the ISS by a Soyuz MS-23 spacecraft next spring.