Former NASA astronaut Scott Kelly has continued his protests against the invasion of Ukraine by returning a Russian space medal.
Kelly has been involved in an ongoing war of words with Dmitry Rogozin, the head of Russia's space agency Roscosmos, following Vladimir Putin's act of aggression against the neighbouring country.
He's now taken that to a new level, returning the medal he received from Russia for his flights on Russia's Soyuz space vehicle.
"Mr Medvedev, I am returning to you the Russian medal 'For Merit in Space Exploration,' which you presented to me," Kelly tweeted.
"Please give it to a Russian mother whose son died in this unjust war. I will mail the medal to the Russian embassy in Washington. Good luck."
Kelly's tweet, in Russian, was in response to former Russian President and Prime Minister Dmitry Medvedev, who tweeted on International Women's Day: "Happy Holidays, dear women! Love, happiness and health."
The retired Navy captain flew twice to the International Space Station (ISS) onboard a Soyuz craft and spent a year in orbit with Russian cosmonaut Mikhail Kornienko in 2015 and 2016.
Kelly speaks Russian, part of a requirement that all ISS visitors need to speak both English and Russian.
The astronaut has also traded barbs with Rogozin, telling the head of the space agency that "maybe you can find a job at McDonald's if McDonald's still exists in Russia".
In a now deleted tweet, Rogozin called the astronaut a moron and said the death of the ISS would be on his conscience.
Rogozin also took exception to Kelly addressing him as 'Dimon', a less formal way of referring to someone called Dmitry.
"Perhaps the dementia and aggression that you have developed is a consequence of the overload and stress of four flights into space," Rogozin hit back.
"I invite you to undergo an examination at the Brain Institute of our Federal Medical and Biological Agency."