Senator Mark Kelly, an Arizona Democrat and former astronaut, visited Ukraine over the weekend and said the United States could not give up on the people there as they fight Russia. Musk responded on X.

Sen. Mark Kelly (D-Ariz.) spent the weekend in Ukraine gathering harrowing information on the impact of President Trump's pause on military aid and information sharing. Why it matters: "When you negotiate the end of a conflict,

Kelly, a former Navy combat pilot, responded to the tech billionaire’s remark by saying “he’s not a serious guy” and should “go back to building rockets.”

U.S. DOGE Service leader Elon Musk on Monday called decorated Navy pilot and former NASA astronaut Sen. Mark Kelly (D-Arizona) a traitor in a post on X after the senator visited Ukraine and expressed his support for the country in its war with Russia.

Elon Musk is being called out by X users for calling Arizona Senator Mark Kelly a "traitor" for showing his support for Ukraine in its three-year war against Russia.

"It's not 'America First' to pull the rug out from under an ally and leave their people to die," Sen. Mark Kelly said after his visit to Ukraine.

In a press release, Kelly "was briefed by U.S. embassy officials and Ukrainian military leaders, visited defense industry sites, heard from wounded service members, and met with the International Red Cross Committee.