President Donald Trump took aim at Elon Musk after his former adviser announced the creation of a new political party following staunch opposition to the president's signature legislation.

Elon Musk said he’s carrying out his threat to form a new political party after his fissure with President Donald Trump, announcing on social media that he would form the America Party in response to the president’s sweeping tax cuts law.

Shares in Tesla tanked by as much as 7.6% in premarket trading Monday after its CEO Elon Musk said he is forming a new American political party, provoking an irate response from US President Donald Trump.