Canadian Prime Minister Justin Trudeau has seen his campaign for re-election hit by a blackface controversy, but the United States' first black president is throwing his support behind the progressive leader.

Former President Barack Obama tweeted Wednesday:

"I was proud to work with Justin Trudeau as President. He's a hard-working, effective leader who takes on big issues like climate change. The world needs his progressive leadership now, and I hope our neighbors to the north support him for another term."

Evidence has surfaced Trudeau has worn blackface costumes in the past, which has hit a campaign already under scrutiny for alleged efforts to pressure officials to drop charges against a Quebec company, according to The Hill.

Canada's Conservative Party candidate Andrew Scheer has closed in amid a tight race, which will be decided at the polls early next week. Trudeau needs to hold 170 of 338 of Parliament's House of Commons seats to keep his majority.

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