The document will take effect from 14 January of the following year. Four more countries of the union, Brunei, Malaysia, Peru and Chile have not yet ratified the agreement.
For them, the deal will take effect 60 days after ratification.
In November, the Vietnamese parliament ratified the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) and related documents, according to local media reports.
The TPP was signed in 2016 and originally brought together 12 Pacific Rim nations, including the United States. However, new US President Donald Trump, who repeatedly criticized TPP during his election campaign, withdrew the country from the deal in 2017, arguing that poorly negotiated trade agreements were harmful to the US job market.