Russia will reject a US request to use the International Space Station after 2020 in retaliation for trade sanctions imposed over Russia's aggressive annexation of Crimea, its deputy prime minister announced today.

The space station is maintained by both American and Russian crews. But because NASA's shuttle program was decommissioned in 2011, the only way to get there is on board Russian spacecraft. The US currently pays Russia $60 million per person to ferry its astronauts to the space station, and had planned to continue working on it until 2024.

"The Russian segment can exist independently from the American one. The US one cannot," Russian deputy prime minister Dmitry Rogozin said today.

The US pays Russia $60 million per astronaut to get to the ISS

The move comes after NASA announced it was cutting off contact with Russia because of the Ukraine crisis, with the exception of the space station. At the time, critics said the move was a ploy by NASA to get more funding from the US government. Russia's announcement, however, seems genuinely motivated by the Ukraine fallout.

Russia will also bar the US from buying Russian rocket engines that would be used to launch military satellites, Rogozin said.

The country is following through on its threats from last month. At the time, Rogozin joked that the US would have to explore using trampolines to send its astronauts to space.

Update, 4:18PM: NASA sent an official statement saying it is not aware of any changes.

Space cooperation has been a hallmark of US-Russia relations, including during the height of the Cold War, and most notably, in the past 13 consecutive years of continuous human presence on board the International Space Station. Ongoing operations on the ISS continue on a normal basis with a planned return of crew today and expected launch of a new crew in the next few weeks. We have not received any official notification from the Government of Russia on any changes in our space cooperation at this point.