Billionaire Elon Musk also attacked US Senator Mark Kelly after the Arizona Democrat expressed his support for Ukraine.
Kelly visited Ukraine over the weekend and pledged his support for the Ukrainian people amid the ongoing war with Russia.
"What I saw proved to me that we cannot give up on the Ukrainian people. Everyone wants this war to end, but any agreement must protect Ukraine's security and cannot be a gift to Putin," Kelly wrote in a post on the social network "X".
In response to the senator's post, Musk simply wrote: "You are a traitor."
Kelly responded to Musk's comment by saying, "Elon, if you don't understand that protecting freedom is a core tenet of what makes America great and keeps us safe, maybe you should leave it to those of us who do."
Kelly, who has made numerous visits to Ukraine since being re-elected in 2022, has said he is working with his colleagues to restore US support for Ukraine.
Ukrainian officials have said that a delegation from Kiev is expected to meet with the top US diplomat in Saudi Arabia soon and will propose a ceasefire with Russia, according to the Associated Press.