Bangkok: Eleven Asia-Pacific nations, including Australia, agreed on Sunday to salvage a massive free trade deal that US President Donald Trump pulled out of days after taking office in January.

Australia's Trade Minister Steve Ciobo pushed for the agreement at a meeting in Vietnam to "launch a process to assess options" to bring the Trans-Pacific Partnership into force.

New Zealand Trade Minister Todd McClay, who chaired the meeting, left open the possibility of the US rejoining the TPP despite Mr Trump saying he prefers bilateral free trade deals.

Mr McClay said each country had to consider both economic values and the strategic importance of the agreement "but in the end there is a lot of unity among all of the countries and a great desire to work together to come up with an agreement."