Kemi Badenoch’s comments came after she signed off the deal with a trade area that covers about 500 million people.
The agreement is predicted to only bring marginal gains to the UK economy.
However, Ms Badenoch told the Sunday with Laura Kuenssberg programme that the key thing was how businesses “utilise the agreement”.
The Comprehensive and Progressive Agreement for Trans-Pacific Partnership - or CPTPP - was established in 2018, and includes Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.
Membership of the CPTPP loosens restrictions on trade between members and reduce tariffs - a form of border tax - on goods.
It is hoped that joining the group will boost UK exports by cutting tariffs on goods such as dairy and meat products, cars, gin and whisky.
Together, the 11 members account for about 13% of the world’s income and the UK has become the first European country to join.
Despite this, the government’s own estimates indicate being in the bloc will only add 0.08% to the size of the UK’s economy in 10 years.
Some benefit … 
Questioned on why the UK has not yet signed a free trade agreement (FTA) with the US, Ms Badenoch said that was due to the change in government.
“Yes, it was expected that we would sign an FTA with the US, but that was with a different president. You cannot force a country to do something if its administration changes.”
Some excuse …