Deputy Prime Minister Somkid Jatusripitak supports Thailand joining the amended Trans-Pacific Partnership agreement in order to gain future trade and investment benefits.
Mr Somkid said on Wednesday that Thailand could miss out on trade and investment opportunities with neighbouring countries, including Vietnam, if the country stays outside the pact.
The deputy prime minister's comments come after the United States, the world's largest economy, hinted it was open to rejoining the pact under certain circumstances. Donald Trump pulled the US out after he became president.
Despite Washington's withdrawal, 11 other members signed an amended version of the pact, called the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, in Chile on March 8.
Brunei, Malaysia, Singapore and Vietnam are the other Southeast Asian members of the TPP, which also includes Australia, Canada, Chile, Japan, Mexico, New Zealand and Peru. Together, the pact signatories represent 13.5% of the global economy -- a number that would greatly increase if the US rejoins.
The Commerce Ministry is analysing the potential costs and benefits of Thailand signing on to the new agreement.
All members of the Association of Southeast Asian Nations, including Thailand, are members of another China-backed trade deal, Regional Comprehensive Economic Partnership, which also includes China, India, Japan, South Korea, Australia and New Zealand.
Mr Somkid said Thailand should be part of both regional trade agreements to protect its economic interests.