The UK has become the first European nation to accede to the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), a trade bloc including Japan, Australia, Vietnam, Malaysia and New Zealand.
Negotiations for the UK to join CPTPP first began in 2021 with the treaty signed by the former government last July.
On Sunday, the agreement entered into force between the UK and members who ratified its accession first: Brunei, Chile, Japan, Malaysia, New Zealand, Peru, Singapore, and Vietnam.
It will start with Australia on 24 December, and with Canada and Mexico 60 days after they each ratify the agreement.
Together, the CPTPP countries have a combined GDP of £12 trillion and are home to more than half a billion people. The UK government says the deal could potentially boost the country's economy by £2 billion a year in the long run. This equates to around 0.08% of UK GDP.
As a result of the agreement, 99% of UK goods exported to CPTPP member countries are eligible for zero tariffs, and UK services firms could also find it easier to export their services.
CPTPP is expected to expand over time, with Costa Rica recently announced as the next country to go through the process of joining.
Business and trade secretary Jonathan Reynolds said: