Speaking to reporters after the first day of a Group of Seven finance leaders’ two-day gathering, Katayama said she had told her counterparts that speculative movements are evident across financial markets.

“I told (them) fluctuations in crude oil prices continue to spill over into foreign exchange rates and government bond yields, and that it remains necessary to maintain vigilance going forward,” she said.

Tokyo is believed to have spent nearly 10 trillion yen (US$63 billion) since launching its latest round of yen-buying intervention starting April 30, marking Japan’s first foray into the market in almost two years.

After rising to around 155 per dollar in early May, the yen has since surrendered more than half of its gains, coming close to the 160 mark which is seen as the Japanese authorities’ line in the sand for intervention.

Katayama said she would not comment on whether Japan had intervened, adding that the issue was not raised during the meeting. “That said, volatility itself was discussed, and its causes include developments in the Middle East as well as speculative behaviour,” she said.

“As we have stated previously, we will respond appropriately at any time if necessary,” she added.