Twelve countries participated in the TPP negotiations: the four contracting parties to the 2005 Trans-Pacific Strategic Partnership Agreement and eight other countries. All twelve signed the TPP on February 4, 2016.  The agreement would have entered into force after ratification by all signatories if this had been done within two years. If the agreement had not been ratified by all by 4 February 2018, it would have entered into force after ratification by at least six states, which together have a GDP of more than 85% of the GDP of all signatories. The U.S. withdrawal from the agreement in January 2017 ended virtually all prospects for the agreement to enter into force. In response, the other parties successfully negotiated a new version of the agreement, which does not have the 85% of GDP threshold, the CPTPP, which came into force in December 2018. According to members of Congress and representatives of the technology industry, the biggest improvement over the TPP came from the U.S.-Japan Digital Trade Agreement. They described it as a “TPP-Plus” and in line with U.S. goals of setting global internet and e-commerce rules.
On January 23, 2017, President Trump signed a memorandum from the President to remove the United States from the TPP.  U.S. Senator John McCain criticized the withdrawal and said, “This will send a worrying signal of U.S. withdrawal in the Asia-Pacific region at a time when we have the least means.”  U.S. Senator Bernie Sanders welcomed this approach, saying, “Over the past 30 years, we have had a series of trade agreements. . . . that cost us millions of decently paid jobs, and created a race to the bottom that brought down the wages of American workers.
 Although the TPP has not been adopted, the agreement had already introduced forms of regulatory cooperation for agriculture that go beyond those found at the WTO.  This means that regulators have come into contact and established trust among various signatories to the TPP.  Chad P. Bown, senior Fellow at the Peterson Institute for International Economics, argues that this regulatory cooperation has resulted in the U.S. poultry industry not being so hard hit by the 2015 avian influenza outbreak, as regulators in TPP countries cooperated and continued to accept U.S. poultry exports.  The U.S.-Japan trade agreement is a step forward. This is the president`s first trade agreement with a major trading partner that, given that its limited scope does not require congressional approval, could soon produce its full effect.
New Zealand ratified the TPP on 11 May 2017.  Prime Minister Jacinda Ardern will attempt to renegotiate the Trans-Pacific Partnership (TPP) agreement in Vietnam in time, so that the government can prohibit foreign speculators from buying existing New Zealand homes. She said, “We believe it will be possible to reconcile our desire to ensure that we provide affordable housing by easing demand and prohibiting foreign speculators from buying existing homes while meeting our business objectives.”  WASHINGTON (Reuters) – The new U.S.-Japan trade deal will gradually reduce Japan`s tariffs on beef and pork by more than $2 billion.