Trade Minister Todd McClay is heading to Vietnam to discuss the future of the Trans-Pacific Partnership deal.
What remains of the deal, which was set to be agreed by 12 countries, has been in danger of falling apart since US President Donald Trump withdrew from it in January.
Mr McClay will hold talks with Vietnam's Prime Minister Nguyen Xuan Phuc on the TPP and a separate deal which includes china, the Regional Comprehensive Economic Partnership.
It is understood Vietnam has been less keen on the TPP since the US pulled out.
The 11 remaining countries, including Vietnam, were expected to be meeting on the sidelines of the APEC Trade Ministers' meeting in two weeks' time.
Japanese media reported the sideline meeting would confirm the future of the TPP - whether it would go ahead, which countries would be involved, and whether it would be renegotiated.