The European Union's top officials on Wednesday formally signed the long fought-over post-Brexit trade deal with the United Kingdom.

European Commission president Ursula von der Leyen and European Council president Charles Michel put pen to paper during a brief signature ceremony in Brussels. The documents will now be flown across the Channel to London in a RAF plane for British Prime minister Boris Johnson to sign them.

``The agreement that we signed today is the result of months of intense negotiations in which the European Union has displayed an unprecedented level of unity,'' Michel said. ``It is a fair and balanced agreement that fully protects the fundamental interests of the European Union and creates stability and predictability for citizens and companies''.

The UK Parliament will later start debating the agreement setting up new trade rules between the 27-nation bloc and former member Britain. It is set to provisionally enter into force on Jan. 1. The agreement eventually needs approval from Britain's Parliament, and from the EU's legislature, which is not expected to take up the deal for weeks.

The leaders of the European Parliament's political groups said they would not seek full approval until March because of the specific and far-reaching implications of the agreement. The overwhelming expectation is that EU lawmakers will approve the deal.

The 1,240-page post-Brexit deal was sealed by the EU and the UK on Christmas Eve, just a week before the year-end deadline.

``On major issues, the European Union stands ready to work shoulder to shoulder with the United Kingdom,`` Michel said. ``This will be the case on climate change, ahead of the COP 26 in Glasgow, and on the global response to pandemics, in particular with a possible treaty on pandemics. On foreign affairs, we will seek cooperation on specific issues based on shared values and interests.``