The nation's currency policy remains unchanged, Finance Minister Masajuro Shiokawa said Tuesday, indicating Japan is prepared to intervene in the foreign-exchange markets to stem the rapid gains by the yen.

"My utmost concern is the movements in the foreign-exchange rates," Shiokawa told a news conference. "We must closely monitor the situation. Our basic policy has not changed."

The dollar plunged against the yen and other major currencies in New York on Monday, falling at one point into the 115 yen range for the first time since February 2001.