The United Kingdom is expected to ask to join the CPTPP agreement tomorrow, which underlines the importance of the deal, and could assist New Zealand's free trade ambitions with them, the government says.
The CPTPP (Comprehensive and Progressive Trans-Pacific Partnership) is a trade agreement between 11 Pacific Rim nations, including New Zealand, Australia, Canada, Japan, Singapore, Malaysia, and Mexico. It covers about 13 percent of the world's income.
Last year the government of the UK signalled it would try to join to to open up diverse opportunities for exporters and "help support an industrial revival in the UK".
UK International Trade Secretary Liz Truss is expected to make the request on Monday.
NZ Minister of Trade Damien O'Connor welcomed the move.
"The challenges facing the global trade and economic environment have been compounded by COVID-19. In this context New Zealand sees the CPTPP objective of maintaining and growing open rules-based trade, as more important than ever," he said.
"New Zealand has always supported the expansion of the CPTPP."
Britain is New Zealand's sixth biggest trading partner, and the countries are currently in negotiations towards a free trade agreement, following the UK's exit from the European Union.
"Both sides see conclusion of a high quality, comprehensive and future-focussed FTA as a valuable stepping stone towards the UK joining the CPTPP," O'Connor said.
The UK previously said becoming part of the Pacific Rim group would ally the UK to "a network of countries committed to free trade, and send a powerful signal to the rest of the world that the UK is prepared to champion free trade liberalisation, fight protectionism and remove barriers at every opportunity."
To start the process towards joining the UK must write to New Zealand, which is acting as the Depository for the partnership. Then member nations will discuss the request, and may form a working group to begin work on negotiations between the UK and CPTPP group.
If the UK joins, the conditions would set a precedent for other countries that may want to join in the future, O'Connor said.
The precursor to the CPTPP was the TPP Agreement, which was signed by then-US President Obama Barack and 11 other member nations. It was in the process of being ratified in member countries before it could be enacted, when Donald Trump came into office and withdrew the US.
Instead the remaining 11 members signed the CPTPP in 2018.
In 2019, the UK sent more than NZ$1.9 (£1billion) worth of exports to countries in the CPTPP.