President Donald Trump has fulfilled a campaign pledge by signing an executive order to withdraw from the Trans-Pacific Partnership (TPP).
The 12-nation trade deal was a linchpin of former President Barack Obama's Asia policy.
"Great thing for the American worker what we just did," said Mr Trump as he dumped the pact with a stroke of a pen.
Mr Trump's executive order on TPP was largely symbolic since the deal has not been ratified by a divided US Congress.
Democratic Senator Bernie Sanders told the BBC he backed it because trade deals like this have been a "disaster" and cost millions of jobs.
What is the TPP?
The trade deal, which covered 40% of the world's economy, was negotiated in 2015 by nations including the US, Japan, Malaysia, Australia, New Zealand, Canada and MexicoTPP's stated aim was to strengthen economic ties and boost growth, including by reducing tariffsIt included measures to enforce labour and environmental standards, copyrights, patents and other legal protectionsThe agreement, backed heavily by US business, was designed to potentially create a new single market likened to the EUCritics argued it was a not-so-secret gambit to box in China, which is not part of the agreement
The Trump administration's first weekday began with a flurry of executive orders, which allow the president to bypass Congress by issuing legally binding directions, mostly of limited scope, to federal agencies.
Mr Trump also signed an order blocking foreign aid or federal funding for any nongovernmental organisation that provides abortions abroad.
The so-called Mexico City policy was first established by Republican President Ronald Reagan in 1984.
It is typically rescinded by incoming Democratic presidents, including Barack Obama in 2009, and reinstated by Republican presidents.
After meeting business leaders earlier at the White House, Mr Trump pledged to lower corporate taxes to 15% or 20%, from the current 35%, and slash regulations by up to 75% if they keep jobs in the US.