The Korean won strengthened to a fresh five-month high against the U.S. dollar Thursday, after the U.S. Federal Reserve held its benchmark interest rate steady.

The won was quoted at 1,437.4 won per dollar at 3:30 p.m., up 9.3 won from the day before, marking the strongest level since Feb. 26.

The won gained after the Federal Reserve left the rate unchanged at the 3.5-3.75 percent range, marking the fifth consecutive pause.

However, three Fed policymakers dissented and called for a hike, raising speculation that a rate hike can occur down the road.

The won's strength was also supported by foreign investors' net purchase of local stocks.

Foreigners bought a net 1.3 trillion won ($900 million) worth of local stocks during the latest trading session, while the benchmark Korea Composite Stock Price Index fell 1.23 percent to close at 5,593.56.