TOKYO (Kyodo) -- The Japanese government will take "decisive action resolutely" when needed, Finance Minister Satsuki Katayama said Friday as the yen fell closer to the 164 line against the U.S. dollar, fueling speculation of intervention by Japanese authorities.

"We will respond appropriately as required," Katayama said, as the yen depreciated to 163.99, its lowest in 39 years and eight months overnight in New York, adding that she would not comment on specific exchange-rate levels.

The yen continues its slide beyond the levels at which Japanese authorities intervened in April and May, with the dollar drawing buying as a safe-haven asset at a time of crisis as tensions in the Middle East heighten due to the U.S.-Iran war.

The yen also faced selling on views that rising crude oil prices would hurt the import-reliant Japanese economy, dealers said.