Asia-Pacific countries hoping to create a regional trading zone as part of the largest-ever trade deal said today they would push on without the United States, despite President Donald Trump's decision to withdraw from the Trans-Pacific Partnership Agreement (TPPA).

"It's a great shame but not unexpected," Australian Trade Minister Steve Ciobo said in response to Trump's decision, adding he was interested in seeing if a TPPA of 12 nations, minus one could work.

Australia would keep alive the option of ratifying the deal and has already had discussions with Canada, Mexico, Japan, New Zealand, Singapore and Malaysia about working towards an alternative, Ciobo said.

"Australia and quite a number of the other TPP countries are very focused on making sure we still capture the gains that were agreed to under the TPPA," he told Sky News television.

New Zealand Trade Minister Todd McClay expressed the same sentiment, saying that his country too would pursue the TPPA with the remaining members.

The agreement still had value as a free trade agreement with the other countries involved, McClay added.

The order to withdraw the US from the TPPA was one of the plans that Trump, who took office last Friday, had outlined for his first 100 days in office. "We've been talking about this for a long time," he said as he signed the document

Without the US, the remaining TPPA members are Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.

The agreement sought to lift key trade barriers in the region and would have eliminated or reduced about 18,000 tariffs on industrial and agricultural goods, including textiles and clothing.

Several other governments of Asian TPPA members have voiced an interest in continuing the agreement without the US.

Including the US, TPPA countries have a combined population of 800 million and account for around 40 percent of the world economy and 26 percent of world trade, valued at more than US$11 trillion.

- dpa