Trade ministers from 11 Pacific Rim countries officially signed the agreement during a ceremony in Chile's capital of Santiago on Thursday.
The deal, now known as the Comprehensive and Progressive Trans-Pacific Partnership (CPTPP), drops Washington's demands for protection of intellectual property and covers some 500 million people living in Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.
Only three days after his inauguration, Trump signed an executive order to withdraw Washington from the negotiating process of the sweeping deal, which his predecessor Barack Obama believed would improve American manufacturing by removing tariffs.
Trump said back then that he would begin to negotiate individual trade deals with the TPP countries instead.
The CPTPP's signing came hours before Trump officially announced steep 25-percent and 10-percent tariffs on imported steel and aluminum respectively, despite warnings of igniting a possible trade war.
Upon signing the paperwork, Trump said the move was a response to unfair practices by America’s trading partners who had orchestrated “an assault on" the US. The tariffs will take effect in 15 days.
Trump temporarily exempted Mexico and Canada from the tariffs, a move aimed at pressing them to give ground in separate talks on the North American Free Trade Agreement (NAFTA), another deal that Trump has been critical of.
The American head of state has in the past warned Mexico and Canada that they may be subject to heavy tariffs if there isn't major progress in the renegotiation of the three-nation pact.
Trump's tariffs are bound to hurt Japan, another CPTPP member, which accounts for five percent of US steel imports. That's twice the share of the world's largest still producer, China.
