U.S. President Donald Trump's decision to impose tariffs on steel and aluminum imports has increased the distance between Washington and the Trans-Pacific Partnership free trade pact.

Japan and the 10 other members remaining in the trade treaty signed the deal on Thursday without the United States, just a few hours before the U.S. president signed the new U.S. trade measures on metal imports.

The 11 countries have left the door open for the world's biggest economy to rejoin the pact, as Trump has suggested that is a possibility since pulling his country out of the deal last year.