The Bank of Korea’s (BOK) Sept. 10 monetary policy report says U.S.-Japan intervention in the foreign exchange market has already helped reverse some yen weakness and expects the Bank of Japan (BOJ) to further tighten interest rates.

A stronger yen and higher Japanese interest rates could lift the won and cut South Korea’s import bill, while also drawing Japanese money home, raising global borrowing costs and exposing Seoul to new financial stress.

The immediate effects look favorable for Seoul. The yen has strengthened sharply this month as markets anticipate another BOJ rate increase, while the won has risen alongside it