On Tuesday, the Japanese yen fell to its record low since November 2022, with the US dollar trading at 144 yen.
"We will closely watch developments in the currency market with a sense of increased urgency and respond appropriately if moves become excessive," Kanda was quoted by Japanese news agency as saying.
Kanda's remarks may precede the government's possible currency market intervention to strengthen the national currency, media reported.
The yen has been in steady decline since March due to the Japanese Central Bank's commitment to monetary easing policy and hikes in interest rates by the US Federal Reserve and other foreign central banks.