LONDON, Dec. 15 (Xinhua) -- Britain and Mexico have signed an agreement aimed to secure the existing bilateral trade following the end of the Brexit transition period on Dec. 31, the British Department for International Trade (DIT) said Tuesday.

The UK-Mexico Trade Continuity Agreement will provide certainty for British and Mexican businesses "trading the goods and services that make up our bilateral trade relationship, which accounts for over 5 billion dollars per year," said the DIT in a statement.

The deal "is intended to be transitional in nature," and both sides agreed to "begin negotiations on a new and ambitious Free Trade Agreement in 2021," the DIT noted.

"Our trade deal with Mexico means we have now secured agreements with 58 countries," tweeted Britain's International Trade Secretary Liz Truss.

Truss said it's Britain's 7th deal with a member of the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), adding "I look forward to the UK applying early next year to join CPTPP."

The CPTPP is a trade pact among 11 countries, with the aggregate gross domestic product (GDP) accounting for 13 percent of the world economy.

The CPTPP entered into force on Dec. 30, 2018 for Australia, Canada, Japan, Mexico, New Zealand and Singapore, and on Jan. 14, 2019 for Vietnam. It will enter into force for Brunei, Chile, Malaysia and Peru 60 days after they complete their respective ratification processes.

The announcement came when trade negotiations between Britain and the European Union (EU) are at a crucial stage as time is running out for both sides to secure a deal before the end of the year. Enditem