British Prime Minister Theresa May will promise to pay a Brexit divorce bill of at least 20 billion euros (£18 billion, $24 billion), the Financial Times newspaper reported on Wednesday.
May's EU adviser Olly Robbins has informed his counterparts in various European capitals of the offer, the newspaper said, citing unnamed officials briefed on the discussions.
The announcement will be formally made by May on Friday, during her highly-anticipated Brexit speech in the Italian city of Florence, the FT said.
However, the German government's spokesman Georg Streiter denied that Chancellor Angela Merkel had received any such notification.
"We have not been informed in advance by the British government of any negotiation offer," he told a regular press briefing in Berlin.
May's Downing Street office called the report "pure speculation".
Britain is yet to put forward a figure to meet its financial obligations to the European Union when it leaves the bloc, currently set for March 29, 2019.
The lack of agreement on a divorce settlement has proven a major stumbling block in the Brexit talks.
While Brussels has not made public its own figure, EU senior officials have told AFP the preliminary evaluation is between 60 to 100 billion euros.
Britain's net contribution in 2015, the last year for which figures were available, was 10.75 billion euros, according to European Commission and European Parliament documents.
The 20-billion-euro figure points to payments to meet the UK commitment to the EU's seven-year budget, which runs to 2020, and could be paid during a transitioned departure from the bloc.
