German Foreign Minister Heiko Maas has slammed US President Donald Trump for sending tweets about a recent meeting of the G7 group of industrialized nations, saying those statements are further destroying trust between the United States and traditional allies in the West.

“You can destroy an incredible amount of trust very quickly in a tweet. That makes it all the more important that Europe stands together and defends its interests even more offensively,” Maas said in his own Twitter page on Sunday, clearly making a reference to Trump’s decision to pull out of a joint communiqué of the G7 summit in Canada.

Trump departed early from Quebec, where the G7 leaders were gathering, on Saturday, saying a more urgent priority for him was an upcoming face-to-face meeting with North Korea's Kim Jong-un in Singapore.

He tweeted again about the G7 from Air Force One, where he was departing for Singapore, saying that the text of the final statement of the summit was not acceptable.

“Europe United is the answer to America First,” wrote Trump in a series of angry tweets about the summit.

The latest episode of the G7 summit was one of toughest ever and the adoption of a consensus statement without the US involvement further tarnished the image of the organization which has traditionally boasted of its shared Western values and objectives under American leadership.

G7 members are especially angry at Trump’s decision in March to impose tariffs on imports of steel and aluminum. Those countries have vowed to reciprocate the move by imposing their own duties on American imports.

The rifts have also widened over Trump’s withdrawal from key international pacts, like a nuclear deal with Iran and a landmark climate change agreement.

Canadian Prime Minister Justin Trudeau said at the end of the G7 summit that his country would not be deterred by Trump’s threats. He said that Canadians “will not be pushed around” over Trump's decision to invoke national security to justify US tariffs.