The won lost as much as 1.2 percent to 1,096.8 per dollar, its weakest since Sept. 6, 2013, after Vice Finance Minister Joo Hyung-hwan made the comments, reported by the financial news arm of South Korea's Yonhap news agency, as the yen hit a seven-year low against the dollar.
Bearish bets on the won rose to the highest since May 2012 in the last two weeks as the yen tumbled after the Bank of Japan unexpectedly eased monetary policy last week, a Reuters poll showed earlier.
The South Korean currency clambered back from its low as
investors covered short positions in regional peers with the dollar down ahead of key events including the European Central Bank policy meeting and US payrolls data.
Malaysia's ringgit advanced as traders said the central bank was spotted intervening to stem its slide.
Some leveraged funds bought the ringgit in non-deliverable forwards markets to take profits from the dollar's recent strength against it.
Investors were awaiting the Malaysian central bank's monetary policy decision later in the day. Bank Negara is expected to hold its key interest rate unchanged at 3.25 percent, according to a Reuters survey.
The dollar slid against a basket of major currencies as investors booked profits following its recent gains against the yen.