UK Prime Minister Boris Johnson has signed the EU Withdrawal Agreement, paving the way for Brexit to take place on January 31.

In what is considered a formality, the European Parliament will vote on the agreement on January 29.

"The signing of the Withdrawal Agreement is a fantastic moment, which finally delivers the result of the 2016 referendum and brings to an end far too many years of argument and division," said Johnson, referring to EU membership referendum four years ago.

"We can now move forward as one country - with a government focused upon delivering better public services, greater opportunity and unleashing the potential of every corner of our brilliant United Kingdom, while building a strong new relationship with the EU as friends and sovereign equals."

Today I have signed the Withdrawal Agreement for the UK to leave the EU on January 31st, honouring the democratic mandate of the British people.



This signature heralds a new chapter in our nation's history. pic.twitter.com/IaGTeeL2is — Boris Johnson (@BorisJohnson) January 24, 2020

Earlier on Friday, Charles Michel, European Council president and Ursula von der Leyen, European Commission president, signed the document in Brussels.

The original copy travelled to London by train and will return to Brussels to be archived. The UK will keep a copy.

Michel tweeted: "Things will inevitably change but our friendship will remain. We start a new chapter as partners and allies."

After Brexit takes place on Thursday, the UK will enter a transition period, during which it will attempt to hammer out deals on future relations with the bloc.

Johnson has stressed that this period must not go beyond the end of 2020, but critics and opposition figures say this deadline is unachievable.