KEY POINTS:
A regional free trade agreement which began two years ago with New Zealand, Singapore, Chile and Brunei could grow to include at least seven countries.
Australia and Peru said yesterday they wanted to join, following the United States' request in September to be involved.
Vietnam has also expressed an interest, but has not yet committed to negotiations to join.
Other Apec countries will be given a deadline of March to decide whether to join the newcomers.
The development was announced yesterday by Chilean Foreign Minister Alejandro Foxley at the Apec trade ministers' meeting in Lima, attended by New Zealand's new Trade Minister, Tim Groser.
The agreement, originally known as the P4, is now called TransPac (the Trans-Pacific Strategic and Economic partnership).
It has overtaken the concept of an Apec-wide free trade agreement for the Asia-Pacific area. The Apec leaders' summit in Hanoi two years ago called for work on this ambitious plan but it has gone nowhere.
TransPac is also the back-door way for New Zealand to achieve a free trade agreement with the United States.
New Zealand's priority will remain the conclusion of the World Trade Organisation's Doha Round.
But maintaining the commitment of the United States through to the next White House Administration is the second, Mr Groser said.
Asked whether the new Administration would be likely to continue with the negotiations after Barack Obama is sworn in as President in January, US Trade Representative Susan Schwab told a press conference she expected it would.
"These negotiations will be launched in March and it will be up to them to proceed.
"The United States has a proud and successful history of having a truly bipartisan trade policy dating back to the Roosevelt Administration and 1934, and it is our hope and expectation that they will continue with that, in that spirit."
Ms Schwab said the Obama team had expressed an interest in high-quality trade agreements.
"They have articulated an interest in trade relations with Latin America and the Asia-Pacific region."
