His comments came as the won's ascent against the dollar has been accelerating, spawning worries it could destabilize the financial market and pose potential risks to the overall economy.
"Foreign currency authorities remain worried about one-sided movement in the won-dollar exchange rates," Vice Finance Minister Choo Kyung-ho told reporters after attending an international conference in Seoul.
"The problem is that the exchange rates could move beyond the ordinary supply-and-demand range when speculative forces join (in the market)," he added. "Authorities are monitoring the market 24 hours a day."
He said that the eased upward pace of the won seen in the last few days reflects the government's strong signal that it "will not sit idle" in the face of what he calls excessive herd behavior.
On Friday, the finance ministry said in a message sent to reporters that it will take "stern" action against speculative forces in the financial market.
The ministry said it held a closed-door meeting with some exporters in Seoul on Tuesday to discuss the won's sharp appreciation and its impact on their business conditions.
The meeting was held between Choi Hee-nam, the head of the ministry's international financial bureau, and officials in charge of foreign currency policies at exporting companies. It was the first of its kind since September last year.
The meeting was intended mainly to listen to their opinions and difficulties from the won's ascent against the greenback, a ministry official explained.
The local currency closed at 1,022.10 on Tuesday, up 2.3 won from the previous session's close. (Yonhap)