Mr Trudeau didn't respond to questions about Mr Trump when the prime minister arrived at a Quebec City hotel today for meetings with other world leaders.
The trade spat has dominated the meeting, with Canada and European leaders threatening retaliatory action in response to United States tariffs on steel and aluminum.
"He (Trudeau) was polarising".
"State of the Union" host Jake Tapper asked Kudlow what right Trump and other US officials had to be offended by Trudeau's comments, given the dispute.
"They should have said to him, 'God speed, you are negotiating with the insane nuclear tyrant in North Korea, and we are behind you, '" Kudlow said.
Donald Trump, in a tirade against countries he said are "robbing" the U.S., targeted India once again on import tariffs, as he left the G-7 summit in Canada on bitter terms. The G-7 also includes Britain, Italy, France, Germany and Japan.
He said the comments were a "betrayal" and "sophomoric".
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Peter Navarro, top White House trade advisor, echoed Kudlow during an interview on Fox news.
"What's not in good faith is when you leave there, you fly out of there, and the host Canadian prime minister starts taking whacks at you, pot-shots at you - on the eve of this Korean summit", Kudlow said.
"To my friends in Canada, that was one of the worst political miscalculations of the Canadian leader in modern Canadian history", Navarro added. And what did Trudeau do as soon as the plane took off from Canadian airspace? John McCain who responded with a very different message for USA allies: "Americans stand with you, even if our president doesn't".
The chancellor said to ARD television: "It's not a pretty thing".
He did him a favour and he was even willing to sign that socialist communique. He should take it back. That will not stand, Navarro said.
But Sen. Lindsey Graham (R-S.C.) said Sunday on ABC's "This Week", "I'm not so sure John's right about where America is on trade". "After many decades, fair and reciprocal Trade will happen!"
Trudeau had announced that the G7 members - Canada, France, Germany, Italy, Japan, the United Kingdom and the US - had agreed upon a joint communiqué, or formal statement, after a hard week on trade issues.
Though other leaders had their own images of the meeting tweeted out, Denzel's photograph - which shows Merkel standing dominantly over a petulant-looking Trump - became the most enduring after it caught the imagination of the web.