Explanation:

The agreement was reached in 2015 among the twelve Pacific Rim countries in the form of largest trade liberalization pact since WTO. TPP is essentially a Free Trade Area.

The 12 countries among which TPP has been agreed upon include – United States, Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, and Vietnam. These countries are home to 800 million people and account for 40% of global trade. It’s no an agreement between ALL the Pacific Rim except Russia & China. Only 12 out of nearly 50+ Pacific Rim countries are part of it.