"He did a great disservice to the whole [Group of Seven (G-7)]", he added.
G7 leaders were hoping for a summit that presented worldwide unity on a number of global issues. He complained that he had been blindsided by Canadian Prime Minister Justin Trudeau's criticism of his tariff threats at a summit-ending news conference.
He really kind of stabbed us in the back.
In an interview Sunday on German public television, Merkel also says European leaders won't be "taken advantage of" on trade.
The statement that Trump reneged on was also signed by the heads of government of Britain, Canada, France, Germany, Italy and Japan, all of which have also been hit by the United States tariffs of 25 percent on imported steel and 10 percent on aluminum.
"He was polarizing", Kudlow said during a Sunday morning appearance on CNN's "State of the Union".
"Canadians are polite, we're reasonable, but we also will not be pushed around", Mr Trudeau said.
Navarro said Trump "did the courtesy to Justin Trudeau to travel up to Quebec for that summit".
But foreign minister Chrystia Freeland said, "Canada does not believe that ad hominem attacks are a particularly appropriate or useful way to conduct our relations with other countries".
Asked whether allies had any reason to worry about Trump's commitment to any deal he reaches with North Korea following his abrupt withdrawal from the G7 communique, one USA official appeared to brush aside the notion, saying other countries have got used to how the president operates internationally.
"That's what matters", he wrote.
"International cooperation can not be dictated by fits of anger and throwaway remarks", he said in a statement. "And anyone who leaves and turns their back on them shows their inconsistency".
Last week, Canada hit back at Trump administration by announcing retaliatory tariffs on up to 16.6 billion Canadian dollars (12.8 billion US dollars) worth of USA steel and aluminum as well as a diverse list of other products. Trump focused his conversation with Macron on German trade for about 15 minutes in the one-hour meeting. Trump said in a second tweet.
- Donald J. Trump (@realDonaldTrump) June 11, 2018Why should I, as President of the United States, allow countries to continue to make Massive Trade Surpluses, as they have for decades, while our Farmers, Workers & Taxpayers have such a big and unfair price to pay?
The joint communique that was thrashed out over two days of negotiations in Canada vowed that members would reform multilateral oversight through the World Trade Organization (WTO) and seek to cut tariffs. "We make commitments and keep to them", a statement from the French presidency quoted by AFP news agency said.
He was reacting to Trudeau's declaration that Canadians would "not be pushed around" and would hit back at punishing United States tariffs on metal imports with "equivalent tariffs".
According to a report by CTV, she said that Canada is "very measured" and that the country's officials "use fact-based arguments" to drive home a point.