Former U.S. President Barack Obama tweeted his support for Canadian Prime Minister Justin Trudeau Thursday.

Wishing my friend @JustinTrudeau the best in Canada’s upcoming election. Justin has been an effective leader and strong voice for democratic values, and I’m proud of the work we did together.

— Barack Obama (@BarackObama) September 16, 2021

Trudeau is up for reelection Monday.

He responded to Obama's tweet by saying, "Progress is on the ballot — and we're going to keep fighting for it."

Thanks for your support, @BarackObama. Progress is on the ballot — and we're going to keep fighting for it. https://t.co/ObjzZBezDh

— Justin Trudeau (@JustinTrudeau) September 16, 2021

Obama also backed Trudeau, the leader of Canada's Liberal Party, in 2019.

The two have similar outlooks. They have both expressed the importance of dealing with health care, gay rights, and climate change.

Obama invited Trudeau to the White House in 2016 after he won his first federal election. It was the first state visit to the White House for a Canadian leader in nearly 20 years.

This year, Trudeau is reportedly locked in a tight race with the Conservative Party's Erin O'Toole.