Billionaire and SpaceX owner Elon Musk was front and center during Donald Trump's inauguration after donating around $200m to get him elected as outgoing President Joe Biden warns of an oligarchy forming.

Elon Musk cheered after newly sworn-in President Donald Trump mentioned Mars in his inauguration speech on Monday. “We will pursue our manifest destiny into the stars,” Trump said, “by launching American astronauts to plant the stars and stripes on the planet Mars.

Elon Musk could be seen making a bizarre gesture in response to US President Donald Trump's pledge to send astronauts to Mars during his inaugural speech.