Elon Musk has told Justin Trudeau he “doesn’t matter” after the outgoing Canadian prime minister dismissed Donald Trump’s plan for the U.S. to take over its northern neighbor. The key adviser to the president-elect jabbed Trudeau on his X social media platform (formerly Twitter) after Canada’s premier announced Monday he is to resign.

Canadian Prime Minister Justin Trudeau announced his resignation after 9 years in office, citing internal party conflicts and declining support. Trudeau and his ex-wife Sophie Gregoire have three children and recently separated after 18 years of marriage.

Trudeau announced his resignation after facing an increasing loss of support from both within his party and in the country.