New Delhi, March 9 -- Elon Musk on Sunday issued a warning to Ukraine, asking the country to stop the war with Russia or face withdrawal of Starlink services, which the tech billionaire called the "backbone" of its defence system.

Musk's warning comes days after he called Ukrainian President Volodymyr Zelensky "evil" for going on with what he called a "forever war" with Russia.

Musk on Sunday in a post on X said that he challenged Vladimir Putin for a physical combat but also has the power to stop Ukraine's access to Starlink.

"I literally challenged Putin to one on one physical combat over Ukraine and my Starlink system is the backbone of the Ukrainian army. Their entire front line would collapse if I turned it off," he said.

"What I...