On a trip to Canada, Mr Tusk proclaimed he was happy to be in a country where citizens don’t say things like “send him back”. The attack was a clear jibe at Donald Trump’s recent twitter activity, in which he told four ethnic minority US congresswomen “to go back to where they came from” rather than tell politicians how America should be governed. Mr Tusk told reporters he was not afraid to criticise the US President despite the risk of sparking further tensions between Washington and Brussels.
The European Council President had been in Canada meeting the country’s prime minister Justin Trudeau.
In a press conference, Mr Tusk said: “Dear Justin, it is a pleasure to be in Montreal, the most European of Canadian cities.
“I really feel at home here, for many reasons, also because in Montreal I didn’t hear anyone shouting, ‘send him back’.”
Mr Trump has been subject to international condemnation for his his media outbursts directed at the Democrat Party politicians.
At a rally on Wednesday, the president’s supporters chanted “send her back, send her back” after the President directed attacks at Ilhan Omar, a Somalian-born US Representative for Minnesota.
Mr Tusk refused to involve himself in US politics but insisted that Mr Trump’s comments have been deeply offensive.
The Council chief said: “I’ve been, for many years, one of the most pro-American politicians in Europe.
“It’s difficult to understand some of those thoughts, words and sometimes if you feel that something is totally unacceptable you have to react despite business, despite interests.
“For me, values are much more important than trade, sorry, maybe I’m old fashioned but I will never change my opinion here.”
Mr Trudeau also joined the attack on his closest neighbour. He told reporters: “The comments made were hurtful, wrong and completely unacceptable.
“I want everyone in Canada to know that those comments are completely unacceptable and should not be allowed or encouraged in Canada.”
The pair were holding talks as part of the 17th summit between the European Union and Canada.
Theresa May has also criticised the President for his recent “unacceptable” outbursts.
Asked about his remarks, Mrs May’s spokesman said: “The prime minister’s view is that the language used to refer to these women was totally unacceptable.”
The spokesman declined to be drawn on whether she thought his remarks were “racist”.
He added that she had no plans to speak to the president before she leaves office on July 24.
Mr Trump has criticised the chants of his supporters in the North Carolina crowd this week.
He said: “I disagree with it. I felt a little bit badly about it.
“I was not happy about it. I disagreed with it but, again, I didn’t say that, they did. I was not happy when I heard the chant.”