U.S. President Donald Trump has posted on his Truth Social account urging Canadians to vote towards becoming "the cherished 51st State of the United States of America".

"Elect the man who has the strength and wisdom to cut your taxes in half, increase your military power, for free, to the highest level in the World, have your Car, Steel, Aluminum, Lumber, Energy, and all other businesses, QUADRUPLE in size, WITH ZERO TARIFFS OR TAXES," he writes.

The U.S. president calls to end an "artificially drawn line from many years ago", adding: "Look how beautiful this land mass would be."

He also says America "can no longer subsidize Canada with the Hundreds of Billions of Dollars a year that we have been spending in the past" unless it is a U.S. state.