German Chancellor Angela Merkel says some British people have “illusions” about discussing the UK’s future ties with the EU at the same time as nailing down the UK’s Brexit terms.

The future relationship can only be discussed once the exit issues – such as UK payments to the EU budget – are resolved, she told German MPs.

On the sequence of the Brexit talks, she said “some people in the UK still have some illusions on that score”.

“That would be just a waste of time.”

EU leaders are to meet on Saturday to adopt their joint negotiating position on Brexit.

Mrs Merkel also insisted that “a third country – which is what the UK will be – cannot and will not have the same rights as an EU member state.

“All 27 EU countries and the EU institutions agree about that,” she told the Bundestag, Germany’s lower house of parliament.

• All you need to know about the UK leaving the EU
• European Parliament’s ‘red lines’
• Brexit: Special report

Mrs Merkel said the immediate Brexit priorities to decide on were the rights of EU citizens in the UK and Britons in continental Europe and Britain’s ongoing financial obligations.

“We can only do an agreement on the future relationship with Britain when all questions about its exit have been cleared up satisfactorily,” she said.

“The sooner the UK government is ready for constructive solutions, the sooner we can meet its wish to talk about the future relationship. But first we need to know how the UK government envisages that relationship. It can only be done in that sequence.”

EU officials estimate that the UK faces a bill of €60bn (£51bn; $65bn) because of EU budget rules. UK politicians have said the government will not pay a sum of that size.

The German chancellor stressed the need to protect the interests of some 100,000 Germans living in the UK.

But she went on to say “we are also ready to make a fair offer to British citizens in Germany and the rest of Europe.

“They are an important part of our community and should remain so.”

Mrs Merkel noted the difficulty of unpicking 44 years’ worth of EU legislation that counts the UK as a member state.

The UK triggered Article 50 on 29 March – the treaty clause that enables a state to leave the EU. It sets a two-year deadline for completion of the exit negotiations.

The EU’s draft guidelines for the Brexit talks were issued on 31 March.

The people who will negotiate Brexit

Brexit timetable:

• 29 April – 27 EU leaders (excluding the UK) meet in Brussels to adopt Brexit negotiating guidelines

• 8 June – UK parliamentary election – Brexit talks to start soon after the vote

• 24 September – German parliamentary election, with Mrs Merkel seeking a fourth term

• 29 March 2019 – Deadline for ending talks on UK exit terms (any extension requires agreement of all member states)

• May or June 2019 – European Parliament election (without UK)

• Ratification – Any Brexit deal requires ratification by all EU’s national parliaments and European Parliament