Boris Johnson has signed the Brexit withdrawal agreement in Downing Street.
The prime minister hailed a "fantastic moment" for the country after he put his name to the historic agreement, which paves the way for the UK's exit from the European Union next Friday.
He said he hoped it would "bring to an end far too many years of argument and division".
Earlier on Friday, European leaders signed the document in Brussels, before it was transported to London by train.
The signings mark another step in the ratification process, following Parliament's approval of the Brexit bill earlier this week. The European Parliament will vote on the agreement on 29 January.