Speaking Wednesday alongside U.K. Prime Minister Boris Johnson before the two leaders held bilateral talks in Berlin, Merkel indicated that a solution for the contentious Irish border issue might yet be reached before the Brexit date of October 31.
"However, Boris Johnson has pinned his political career to leaving the European Union on 31 October and, faced with pressure from the Brexit Party, is unlikely to waver from this commitment".
Former British Prime Minister Theresa May negotiated the withdrawal agreement with the European Union, but it was rejected by the U.K. Parliament three times.
Britain's pound, sensitive to the prospects of a no-deal departure, promptly fell to near three-year lows against the euro and the dollar. "If you want to find these solutions in the future, you can also find them in the short-term". "Even if they do not admit it", Tusk wrote on Twitter.
On Saturday, Mr Johnson will be at the G7 summit in Biarritz, France, where he will meet other world leaders, including US President Donald Trump.
A French diplomat says Britain's no-deal exit from the European Union at the end of October now is the central scenario.
Speaking alongside Merkel before the two leaders held talks, Johnson acknowledged that the onus was on Britain to put forward proposals that would satisfy both sides.
Johnson said the backstop also threatens the peace process in Northern Ireland because it would give control of large parts of the economic and commercial life of the province to an external body, thus "weakening the delicate balance" between its rival factions.
Earlier this month, senior Trump aide John Bolton visited London carrying a message from his boss that the U.S. would set aside foreign policy differences and focus on doing whatever it could to help Britain through the Brexit process. Johnson's government is propped up by Northern Irish unionists.
He was quoted as saying that "I therefore think there's little likelihood that negotiations will get going again".
"Clearly we can not accept the current withdrawal agreement, arrangements which either divide the United Kingdom or lock us into the regulatory and trading arrangements of the European Union. without the United Kingdom having any say on those matters", he said in Berlin.
"We talked about Brexit and how we can move rapidly on a US-UK free trade deal".
Posting on Twitter the group said ending freedom of movement abruptly, before all EU citizens in the United Kingdom can be issued with a status under the EU Settlement Scheme will create two sets of EU citizens - one set who have the automatic right to live and work and those who arrive after 31 October who haven't.
Johnson said Britain and Germany stood shoulder to shoulder on many global issues, including in North Atlantic Treaty Organisation and in the fight against climate change.
In a call with Johnson, Irish Prime Minister Leo Varadkar reiterated the EU's position that the Withdrawal Agreement can not be reopened.
Johnson wants to scrap a contentious clause created to prevent the return of checks along the Irish border, which London says could leave Britain tied to the bloc indefinitely.
Given the shock and dismay Brexit has sparked in continental Europe, its vocal champion, the flamboyant former London mayor and ex-foreign minister Johnson, is sure to meet political headwinds.
In Washington, US President Donald Trump, who has been enthusiastic about Brexit but critical of May's negotiating strategy, offered Britain help while criticising the EU.