President Donald Trump claimed that Canada was "considering" becoming the 51st state in order to be included within his proposed "Golden Dome" missile defense program in a post shared on his Truth Social account Tuesday (May 27).

"I told Canada, which very much wants to be part of our fabulous Golden Dome System, that it will cost $61 Billion Dollars if they remain a separate, but unequal, Nation, but will cost ZERO DOLLARS if they become our cherished 51st State. They are considering the offer!" Trump wrote.

Trump's claim came hours after King Charles III, who rules over Canada and 14 other countries, had rebuked the president's recent comments, claiming that "Canada is facing challenges that, in our lifetimes, are unprecedented" and added that "many Canadians are feeling anxious and worried about the drastically changing world around them." The president had previously taunted that Canada could become the 51st state, addressing then-Prime Minister Justin Trudeau as "governor," amid his proposed 25% tariff on Canadian imports sent to the U.S.

Trump is reported to have had better relations with current Prime Minister Mark Carney, but still pushed for the expansionist idea while hosting him at the White House on May 3.

“I say, ‘Never say never,’” Trump told Carney via the New York Post. “I’ve had many, many things that were not doable and ended up being doable.”

Trump's proposed Golden Dome System intends to protect the U.S. from ballistic, cruise and hypersonic missiles and calls for the current budget to allocate $25 billion, with a projected cost of $175 billion in total, according to Aerospace Testing International.