NASA cut some communication channels with Russia over the annexation of Crimea by Moscow, news reports said on Wednesday.

“Given Russia’s ongoing violation of Ukraine’s sovereignty and territorial integrity, NASA is suspending the majority of its ongoing engagements with the Russian Federation,” NASA said in a statement, quoted by space.com.

“NASA and [Russian counterpart] Roscosmos will, however, continue to work together to maintain safe and continuous operation of the International Space Station” (ISS), the statement said.

There are currently two US astronauts on the ISS. The United States has relied on Russian rockets to put its astronauts into space since the end of its own shuttle programme in 2011.

The suspension also does not affect meetings held outside Russia that may include Russian officials, the space.com report said.

It will put a halt to mutual visits between Russian and NASA officials, as well as emails and teleconferences, according to the letter from a top NASA official.