Angela Merkel has said Brexit negotiations should go ahead as scheduled in nine days' time - despite the UK being plunged into political turmoil by the general election.
The German chancellor said the European Union wants talks to progress "quickly" and warned it will defend the interests of its members during the looming divorce proceedings.
After calling a snap election in a bid to strengthen her hand, Theresa May now faces having to tear up her plans - should she cling on to power long enough to set them in motion.
Speaking during a visit to Mexico, Mrs Merkel ended her brief period of "polite" restraint from commenting on Mrs May's catastrophic poll.
"We are ready for the negotiations. We want to do it quickly, respecting the calendar," she said in comments reported by Sky News.
"We were waiting for the election in Britain, but in the next few days these talks will begin. We will defend the interests of the 27 member states, and Britain will defend its own interests."
On Friday, European Council president Donald Tusk warned Mrs May there is "no time to lose".
With talks due to start in Brussels on June 19, Mr Tusk said it was their "urgent task" to get on with the negotiations in "the best possible spirit".
In a letter to the PM congratulating her on her reappointment, he said the two-year time frame set out under Article 50 of the EU treaties left no room for delay.
European Commission president Jean-Claude Juncker also said he hoped there would be no further delay to the negotiations "we are desperately waiting for".
Brussels' chief negotiator Michel Barnier has said the talks would begin when Britain was ready, suggesting he would consider a short delay.
"Brexit negotiations should start when UK is ready; timetable and EU positions are clear. Let's put our minds together on striking a deal," he said on Twitter.
However there was clear frustration with the EU at the failure of the election to deliver a decisive result.
The European Parliament's Brexit co-ordinator, Guy Verhofstadt, said: "Yet another own goal, after Cameron now May, will make already complex negotiations even more complicated."
Mrs May's plans laid in tatters on Friday after an unexpected surge in support for Labour saw the Conservatives lose seats, falling short of an overall majority.
As Mrs May sought to secure a parliamentary majority by striking a deal with Northern Ireland's DUP, a spokesman for Mrs Merkel said they would refrain from commenting out of "politeness and respect".