Finance Minister Dominic LeBlanc said Wednesday that U.S. president-elect Donald Trump’s assertions that Canada should become the 51st state should be taken seriously, after he initially dismissed them as a joke.

Canadian official Dominic LeBlanc criticized President-elect Trump’s “51st state” remarks Wednesday, saying they were no longer funny. “The joke is over,” said LeBlanc, Canada’s finance and intergovernmental affairs minister.

The president-elect keeps floating the idea that Canada, which is home to more than 40 million people and is a founding NATO partner, should join the U.S.