A Downing Street spokesperson said:

The Prime Minister spoke to Chancellor Merkel earlier this afternoon to update her on the ongoing investigation into the Salisbury incident.

The Prime Minister set out the conclusion reached by the UK Government that it was highly likely that Russia was responsible for the attack against Sergei and Yulia Skripal.

They discussed the pattern of aggressive Russian behaviour and agreed it would be important to act in unison with allies to counter it.

Chancellor Merkel condemned the attack and said she stood in full solidarity with the UK.

They agreed that the international community should coordinate closely as the investigation developed and in the wake of Russia’s response.

https://www.gov.uk/government/news/pm-call-with-chancellor-merkel-13-march-2018