The UK must not allow itself to be "blackmailed" by the EU over its Brexit settlement bill, International Trade Secretary Liam Fox has said.
Talks on the final settlement should begin as soon as possible "because that's good for business", Mr Fox said.
Businesses around the world have become impatient with the slow progress of the negotiations, Mr Fox added.
EU negotiator Michel Barnier said there had been little progress on key issues, and trade talks were "quite far" away.
Talks between the UK and EU have stalled over the failure to agree the UK's so-called divorce bill.
The UK wants to begin trade talks and discuss the future relationship between Britain and the EU as soon as possible, saying it would benefit both sides.
However, Brussels insists that discussions about the future relationship can begin only once "sufficient progress" on the "divorce fee", citizens' rights, and the border between Northern Ireland and the Irish republic.
Mr Barnier said that at the current rate of progress, he was quite far from being able to recommend opening parallel talks on a future trade relationship.
No figure has yet been put on the divorce payment, but European Commission president Jean-Claude Juncker has suggested it could come in at about 60bn euros (£55bn).
Unconfirmed reports have put it as high as 100bn euros (£92bn).
Britain, which voted to leave the EU in June 2016, officially began Brexit talks on 19 June this year and is due to leave the EU on Friday, 29 March 2019.
Speaking in Japan on Friday, Mr Fox said everyone would benefit from Brexit if the outcome was free trade with no tariff barriers.
Asked whether it was time for the UK to name its Brexit price, he told ITV News: "We can't be blackmailed into paying a price on the first part (the divorce fee).
"We think we should begin discussions on the final settlement because that's good for business, and it's good for the prosperity both of the British people and of the rest of the people of the European Union."
Mr Fox and Prime Minister Theresa May have been holding talks with Japanese leaders about the future of trading relations between the two countries after Brexit.
'Unlock some tension'
Speaking to the BBC at the end of the three-day visit, Mr Fox said: "It's very clear that businesses, not just in Europe but investors in places like here in Japan, are getting impatient and want to see what that final shape of that [Brexit] arrangement is going to be."
He said a willingness by the EU to negotiate on the future trading relationship now would "unlock some of the tension".
He added that it was a "mistake" for the EU to think a delay in talking about the economy and the trading arrangement would not potentially damage them too.
But writing in the Daily Telegraph on Friday, Belgian MEP Guy Verhofstadt, who heads Parliament's Brexit group, said the EU has been "fully transparent" about its negotiating positions and mandates since day one.
"This is not a ploy to derail talks, but an inevitable consequence of the Brexit decision," he said.
Mr Verhofstadt called on UK politicians to "be more honest" about the complexities of Brexit negotiations, asking them to recognise that "other governments also have obligations to their own taxpayers".
Speaking on Thursday following talks in Brussels with Brexit Secretary David Davis, Mr Barnier said the UK did not feel "legally obliged to honour its obligations" after Brexit.
He said "no decisive progress" had been made on key issues, following the third round of talks.
Mr Davis said the UK had a "duty to our taxpayers" to "rigorously" examine the EU's demands.
And he urged the EU to be "more imaginative and flexible" in its approach.
