Boris Johnson and Ursula von der Leyen have failed to reach agreement on UK demands to reshape post-Brexit arrangements in Northern Ireland.
The PM and president of the European Commission spoke earlier about the UK's suggested changes to the Northern Ireland protocol.
Ms von der Leyen said that the EU will "not renegotiate" the original deal.
But a Downing Street spokesman said the PM reiterated the protocol is "unsustainable" and must be changed.
Mr Johnson also urged German Chancellor Angela Merkel to consider "significant changes" to the agreement during a call on Thursday, No 10 said.
https://www.bbc.co.uk/news/uk-politics-57930799