The Japanese yen weakened past 157 to the dollar on May 23, hitting a three-week low after the US purchasing managers index showed accelerated business activity.

S&P Global's PMI survey exceeded market expectations, prompting dollar-buying among traders confident in a resilient US economy.

After falling to 160 against the dollar on April 29, the yen surged to 151.80 on May 3, likely due to market intervention. However, it has since weakened, influenced by dollar-buying from Japanese importers and carry trades.

The yen also weakened to the 170 range against the euro on May 23, a low not seen since April 29.