The head of the European Commission and Council, Ursula von der Leyen and Charles Michel on Friday signed UK Prime Minister Boris Johnson’s Brexit deal, ahead of the country’s exit from the EU on January 31.

The development comes a day after Queen Elizabeth II on Thursday approved the European Union (Withdrawal Agreement) Act, and on January 29, the European Parliament is expected to vote for it too, the BBC reported.

Following the signing, taking to Twitter, Michel said, “things will inevitably change but our friendship will remain.

“We start a new chapter as partners and allies,” he added.

On January 23, the House of Commons (lower house of British parliament) overturned five amendments to the government’s Brexit bill made by the House of Lords (upper house), less than 10 days before Britain is set to exit from the European Union (EU).

The House of Lords will later consider the rejection of its amendments. Observers say the solid support in the House of Commons makes the Brexit bill unstoppable.

The bill, which ensures Britain leaves the EU on Jan. 31, will pass between the Houses until both sides agree on the wording. Once the process is finished, it will go to the palace for Royal Assent by Queen Elizabeth II.

Earlier in the month, during a meeting with the new European Commission (EC) chief Ursula von der Leyen, PM Johnson stressed on the importance of Britain and the European Union (EU) to reach a trade deal by the end of the year.

Once the UK leaves the EU on January 31, the two sides will begin talks on their future economic relationship.

Brexit Secretary Stephen Barclay said that the UK and EU had agreed in the political declaration to do a trade deal by the end of this year and they were “confident” they will do that, the BBC reported.

The UK has an option to extend the transition but Johnson refuses to, and intends to enshrine the 2020 date in legislation, PM Johnson’s office said.

After Johnson claimed huge victory, European leaders will charge EU negotiator Michel Barnier with negotiating a close trade deal with Britain.

A landslide Conservative win would mark the ultimate failure of opponents of Brexit who plotted to thwart a 2016 referendum vote through legislative combat in parliament and prompted some of the biggest protests in recent British history.

Johnson was re-elected Prime Minister following his landslide victory in the December 12 general election, deemed as one the UK’s most decisive and crucial.

(With inputs from agency)