German chancellor Angela Merkel has described as “sobering and a bit depressing” US president Donald Trump’s collapse of the G7 meeting via Twitter.

Dr Merkel came out fighting on her return to Berlin, insisting the latest Trump about-turn was a fresh reminder that Europe must become even closer amid a looming trade war.

“We won’t allow ourselves be had again and again,” she told ARD public television on Sunday evening, insisting the EU would press ahead with counter-measures to US tariffs on European steel and aluminium. The bloc is expected to announce its plans on July 1st.

In her strongest comments yet, she criticised the US president for dashing an “arduously negotiated” G7 summit declaration via social media.

“Reneging in a tweet is sobering and a bit depressing,” said Dr Merkel. “It’s difficult, it was disappointing this time, but it’s not over. Sometimes it seems the American president thinks that only one side wins and everyone else loses.”

After 18 months struggling to cope with the Trump administration, Dr Merkel renewed her call to European allies to find new ways of working together and with other countries beyond the US.

“We as Europe have to stand up for our principles, potentially together with Japan and Canada, ” she said.

“We have to ask ourselves the question: ‘where can we act alone?’” she said. “Loyalty first apples to one’s own country but the second loyalty – when it has to do with foreign political decisions – should lie with the EU.”

Germany’s economics minister, Peter Altmaier, said he would continue to work to avoid a trade war but admitted that “no solution is in sight, at least not in the short term”.

“With the rejection of the G7 summit declaration,” he told German national radio, “we have gone backwards.”

Conciliatory gestures

In her lengthy television interview, Dr Merkel said would continue to engage with the Trump White House – “there are too many good reasons to” – and made two conciliatory gestures to Mr Trump. The first: the German leader said she “wished” the US and Russian leaders would meet “for an extended period of time”. At the G7 meeting, other leaders dismissed Mr Trump’s calls for Moscow to return to what was once the G8.

In a second gesture she conceded that Europe, if it was to do more for its own security, would have to spend more on it.

She said Mr Trump was “right to a certain extent” for criticising Germany for spending only 1.3 per cent of economic output on defence. Given that, she said, “we need to increase our defence budget”.

The G7 debacle increases the stakes in a looming trade war, certain to hit Germany’s auto industry, which employes more than one million people.

On Monday, as senior Daimler managers were hauled in to explain irregularities in emissions tests, Bavarian prosecutors investigating that affair announced they had raided the home of Audi chief executive Rupert Stadler.

Dr Merkel returned to Germany from Canada to a bad-tempered war of words with her Bavarian allies, the Christian Social Union (CSU), after another violent attack with an asylum seeker suspect.

German police say a 20 year-old man from the Kurdistan region of Iraq has admitted to the rape and killing of a 14-year old German girl, Susanna Feldmann. Her body was found last Wednesday in a wooded area in Wiesbaden, near Frankfurt.

Asylum rules

Iraqi authorities extradited the man, identified as Ali Bashar, on Saturday after he was taken into custody on Friday. He had sought asylum in Germany and stayed on after the application as refused. He left Germany together with relatives earlier this month.

The 20-year-old came to Germany in 2015, at the height of the refugee crisis, and was known to police for violent behaviour and was a suspect in the rape of an 11-year-old girl at a refugee centre.

Senior conservatives in Dr Merkel’s Christian Democratic Union (CDU) have, in wake of the Feldmann killing, called for a full investigation into rules for asylum, refuge and integration.

But CSU plans to present tougher new asylum rules on Tuesday were cancelled after reports of considerable disagreement between the party chairman, interior minister Horst Seehofer, and Dr Merkel.