As tensions between the US and Russia over its invasion of Ukraine rise, Russia has threatened to leave an American astronaut stranded in orbit.

In three weeks, astronaut Mark Vande Hei, who holds the record for the longest space journey, will land in Kazakhstan with two Russian cosmonauts on a Russian spacecraft, bringing his 355-day mission to a close.

However, in a video broadcast to social media in late February, Dmitry Rogozin, the head of Russia’s Space Agency and a close ally of Russian President Vladimir Putin, threatened to abandon Vande Hei in space and disconnect Russia’s section of the space station entirely.

The video, which was uploaded by a Russian state news agency, shows Russian cosmonauts waving goodbye to Vande Hei in space before disconnecting the Russian component of the International Space Station from the American segment. Another video showed technicians on a Russian rocket hiding the American flag.

Former NASA astronaut Scott Kelly, who spent nearly a year aboard the International Space Station in 2015 and 2016 and has logged more than 520 days in space, traded barbs with Rogozin on Twitter over the posts.

In late February, NASA stated that the Biden administration’s sanctions against Russia will not jeopardize ISS operations, that no changes are anticipated, and that the agency will continue to support ongoing in-space and ground-based operations.