As Elon Musk and President Donald Trump traded jabs on their rival social media platforms, their feud has escalated beyond a public spat, threatening billions of dollars in federal contracts and throwing the future of America's space program into question.

Elon Musk said SpaceX would decommission its Dragon spacecraft "immediately" after Trump threatened his government contracts in their online feud.

"The easiest way to save money in our Budget … is to terminate Elon's Governmental Subsidies and Contracts," Trump said in a post.