WELLINGTON, New Zealand (AP) — Britain on Sunday officially joined an Asia-Pacific trade group that includes Japan and 10 other nations during a meeting in New Zealand.

The trade bloc covers more than 500 million people and 15% of the world’s economy. For Britain, it represents the largest trade deal it has struck since leaving the European Union more than three years ago.

Britain first announced in March it had reached an agreement to join the bloc, which was created in 2018, after more than two years of negotiations. It is the first new member to join the bloc, called the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP).

It also includes New Zealand, Australia, Brunei, Canada, Chile, Malaysia, Mexico, Peru, Singapore and Vietnam.

“We are honored to become the CPTPP’s first new member and to join this extraordinary community of now 12 economies spanning Asia, the Pacific and now Europe," said British Trade Minister Kemi Badenoch. “This is a modern and ambitious agreement and our membership of this exciting, growing and forward-looking bloc is proof that the UK’s doors are open for business.”

Badenoch said that more than half a million Britons already work for companies from the bloc's member nations.

Shigeyuki Goto, Japan's economic minister, said adding Britain would strengthen the bloc.

“The fact that this was done in a way that maintains the high standards of agreement sets an exemplary precedent for future accessions,” Goto said.

The deal comes as Britain pursues greater engagement with the Indo-Pacific. Critics say the deal is insignificant compared to Britain’s trade with its neighbors in the 27-nation EU.

New Zealand Prime Minister Chris Hipkins said the addition of Britain to the bloc was great news for the region.

“Trade is not only a priority for this government, but is essential to our economic recovery, and improving the lives and livelihoods of all New Zealanders,” Hipkins said.

Since leaving the EU, Britain has also signed separate trade deals with Australia and New Zealand.

The U.S. is not part of the bloc after former President Donald Trump withdrew from its predecessor, the Trans-Pacific Partnership. China has applied to join the bloc.