"It was clear today that we need substantial progress by October and that we then aim to finalise everything in November", Dr Merkel told reporters as the summit ended.
Britain's Prime Minister Theresa May and Ireland's Prime Minister, Taoiseach Leo Varadkar attend a bilateral meeting during the informal summit of European Union leaders in Salzburg, Austria, September 20, 2018.
May wants to keep the United Kingdom inside the bloc's single market for goods, but not services. The 27 heads of other European Union countries got together to reject Theresa May's Chequer's plan, heating up the negotiations weeks away from the deal deadline.
May's plan involves keeping parts of the single market after Britain leaves the European Union but she has been told it can not be cherry-picked.
"Not least because it risks underlining the single market..."
Paul Whiteley, a professor of politics and government at the University of Essex, explains the latest on the unfolding Brexit process.
May on Thursday promised new proposals to reassure Dublin that it would not get a "hard border" with Northern Ireland but said that she too could live with a no-deal outcome. Failing to do so could disrupt the lives of people and business on both sides, and undermine Northern Ireland's hard-won peace.
Humiliation for May as European Union rejects Brexit plan
Tusk said the " moment of truth " on the negotiations was less than a month away, at the October meeting of the European Council. Tusk held open the prospect of an "extraordinary summit" in November to formalise the deal.
"It has been clear for weeks that Theresa May's Chequers' proposals can not deliver the comprehensive plan we need to protect jobs, the economy and avoid a hard border in Northern Ireland", he said.
However, May repeated her warning that Britain would never agree to any "legal separation of the United Kingdom into two customs territories".
Tusk said May has just four weeks to amend her plan - or perhaps face the dreaded prospect of leaving the European bloc with no deal - the so-called doomsday scenario.
If it left without a deal, the country would move from seamless trade with the European Union to customs arrangements set by the World Trade Organization for external states.
Her former Brexit Minister David Davis has warned that there is, what he called, a rock solid core of 40 MPs who would vote against any plan reached under Mrs May's Chequers proposals.
In his press conference last night, Mr Macron said: 'Brexit is the choice of the British people and it is a choice pushed by certain people who predicted easy solutions, ' he said in Salzburg, ' he said. 'They left the day after so as not to have to deal with it.' He did not specify who he was referring to but Ukip leader Nigel Farage quit days after the Brexit referendum.
It all suggests a fractious summit in Brussels next month.
"If Brexit tells us one thing.it shows us that those who say: one can do easily without Europe, that it will all go well, that it is easy and will bring lots of money - are liars", Macron said.