Donald Trump says Canadian prime minister Justin Trudeau has “learned” a lesson after criticising him, and it will cost Canada “a lot of money”.

At a news conference on Tuesday after his summit with North Korean leader Kim Jong Un, the US president recounted his recent exchanges with Mr Trudeau.

He said the Canadian leader must not have realised Mr Trump had televisions on Air Force One, allowing him to monitor Mr Trudeau’s news conference at the end of the G7 summit.

“He learned. That’s going to cost a lot of money for the people of Canada. He learned,” Mr Trump said, wagging his finger. “You can’t do that. You can’t do that.”

The president said he was annoyed by Mr Trudeau’s comments about not letting Canada get pushed around.

“I see (on) the television that he’s giving a news conference about how he will not be pushed around by the United States. And I say, push him around? We just shook hands. It was very friendly,” Mr Trump said.

The president said he had a “good relationship with Justin. I really did”.

But he called Mr Trudeau “dishonest” and “weak” in tweets following the summit on Saturday.

Trump advisers also took up the attack in appearances on Sunday’s news shows, levelling more withering and unprecedented criticism against Mr Trudeau, branding him a backstabber unworthy of Mr Trump’s time.

“There’s a special place in hell for any foreign leader that engages in bad faith diplomacy with President Donald J Trump and then tries to stab him in the back on the way out the door,” trade adviser Peter Navarro said.

Asked about Mr Trump’s remarks in the Canadian parliament on Tuesday, Mr Trudeau said he supports his efforts on North Korea and looks forward to the details of the agreement.

“On his comments, I’m going to stay focused on defending jobs for Canadians and supporting Canadian industries,” Mr Trudeau said before walking away from reporters.

Mr Trump also commented at the news conference on the viral photo taken of German Chancellor Angela Merkel and others standing before him.

Angela Merkel speaks with Donald Trump at the G7 meetingAngela Merkel speaks with Donald Trump at the G7 meeting (Jesco Denzel/German Federal Government/AP)

Mr Trump said it was snapped as they waited for changes he had requested to the communique he ended up pulling out of.

He said it “didn’t look friendly” but it was “very friendly”.