“As Canadians, we are polite, we’re reasonable, but also we will not be pushed around.”

What: Canadian Prime Minister Justin Trudeau on Saturday announced his plan to impose retaliatory tariffs against the United States, saying he would not be "pushed around" by US President Donald Trump. 

Trudeau made the comments in the final press conference of the two-day Global Seven summit hosted over the weekend in Charlevoix, Quebec. The leaders of the world's seven biggest economies attended. 

The announcement was a reaction to Trump's decision last week to impose new tariffs on steel and aluminum products on US allies, including Canada.

“I have made it very clear to the president that it is not something we relish doing, but it is something that we absolutely will do,” Trudeau said. “As Canadians, we are polite, we’re reasonable, but also we will not be pushed around.”

Trump responded hours later with a pair of angry tweets, saying he would no longer sign a statement with the other G7 leaders and threatening to step up his trade war on Canada and Mexico while calling Trudeau "very dishonest and weak." The tweets came shortly after the president left the summit early to prepare for an upcoming meeting with Kim Jong Un in Singapore on June 12.

A spokesman for Trudeau responded Sunday with a more measured tweet, saying, "The prime minister said nothing he hasn’t said before — both in public, and in private conversations with the president."

Why: Trump's outburst against Trudeau unwound a weekend of tense diplomacy with the United States' closest allies -- which yielded a variety of colorful internet memes. It was in keeping with the president's "America First" approach to geopolitics, which thrills his supporters and worries his critics. 

French President Emmanuel Macron said Sunday of Trump's comments, "International co-operation cannot be dictated by fits of anger and throwaway remarks."