The U.S. space agency NASA says it is severing ties with Russia due to the crisis in Ukraine, except for the International Space Station (ISS).
According to a memo sent to workers, NASA employees cannot travel to Russia or host visits until further notice.
They are also barred from emailing or holding teleconferences with their Russian counterparts.
In a statement late yesterday, however, the agency said it will continue to work with its Russian counterpart, Roscosmos, to "maintain safe and continuous operation" of the ISS.
Since the retirement of the space shuttle, Russia's Soyuz spacecraft have been the sole means of transport to the ISS for the world's astronauts.
Also yesterday, the State Department said it had suspended “several” bilateral projects with Russia and will hand over funding for the initiatives to Ukraine.
With reporting by AFP and AP