White House economic adviser Larry Kudlow on Sunday said Canadian Prime Minister Justin Trudeau "double-crossed" the U.S. after the G-7 summit meeting last week by announcing retaliatory tariffs.

Trudeau on Saturday said in a news conference that Canada "will not be pushed around" and announced he would place new taxes on U.S. imports in response to tariffs Trump had placed on metals from multiple countries, including Canada.

"I personally negotiated with Prime Minister Trudeau who, by the way, I basically like working with, but not until this sophomoric play," Kudlow said on CNN.

He said that Trudeau was "polarizing" in his statement and that "he really kind of stabbed us in the back."

Trump himself responded to Trudeau on Twitter, saying, "PM Justin Trudeau of Canada acted so meek and mild during our @G7 meetings only to give a news conference after I left saying that, “US Tariffs were kind of insulting” and he “will not be pushed around.” Very dishonest & weak. Our Tariffs are in response to his of 270% on dairy!"

[Related: Trump dings Canada before G-7 trade talks: 'Not fair to our farmers!']