Canada’s liberal Prime Minister Justin Trudeau has regularly had run-ins with President Trump.

The two world leaders are often in a war of words on social media over issues that impact both countries, such and NAFTA and the Paris Climate Accords. Just last week, Canada imposed tariffs on some American products in response to the Trump administration waging a tariff war of their own on overseas products.

Trudeau was on “Meet The Press” Sunday morning and shared the advice President Obama gave him before leaving office.

Trudeau said Obama implored him to “defend” their values “not just our citizens, but citizens around the world in positive ways.”

.@JustinTrudeau on Obama’s advice to him: “That need to be firm about projecting our values and defending not just our citizens, but citizens around the world in positive ways is what I consider the responsibility we have as Canadians and what I’ll do as leader.” #MTP — Meet the Press (@MeetThePress) June 3, 2018

Trudeau was extremely close with former President Obama, and the two have remained close since Obama left office.

In response, Donald Trump Jr. came in with the “America First” hammer.

Don Jr. replied on twitter, saying, “That’s one ideology.”

Trump continued, “I voted for a President that will put my fellow Americans first. Once we solve our problems we can focus on others but not till then.”

That’s one ideology. I voted for a President that will put my fellow Americans first. Once we solve our problems we can focus on others but not till then. #AmericaFirst https://t.co/PgRuJtqbVI — Donald Trump Jr. (@DonaldJTrumpJr) June 3, 2018

The Trump administration has certainly taken this to heart. In the month of May, the Trump administration received the most positive jobs report for the country overall in decades.