The yen surged, erasing earlier losses, after Japan’s currency czar issued another warning about its weakness. The Japanese currency rose as much as 0.4% to 156.51 per dollar, hitting the strongest level since Sept. 18, after a Reuters interview with the nation’s top currency official Atsushi Mimura. He said Japan’s prime minister and finance minister, along with the US, have recently sent a “very clear” message about the yen’s depreciation.

Mimura’s remarks add to a series of government warnings amid renewed pressure on the yen. Prime Minister Sanae Takaichi said US President Donald Trump shared concerns about the yen’s weakness when they met last week. Finance Minister Satsuki Katayama also held a phone call with US Treasury Secretary Scott Bessent Friday evening, reaffirming their view that the yen is undervalued and agreeing to further strengthen cooperation between Japan and the US. “That should make the market sufficiently nervous about potential actual interventions by the MOF in the near term,” said Yusuke Miyairi, FX strategist at Nomura International.

Mimura added that markets should take that message at face value, saying he would be watching closely to see whether they do, according to Reuters. He declined to comment on whether authorities are ready to intervene in the market again, while saying he remained neither satisfied nor reassured by the yen’s recent moves, hinting at the possibility of further actions. For Nomura’s Miyairi, the fact that the country’s top currency official had waded into the conversation against the yen’s constant decline suggested that the Japanese authorities may be preparing to enter the market to stem the currency’s weakness.

Such a move would come after Tokyo and Washington in July conducted their first joint intervention in 15 years to prop up the yen, with Japan alone spending a record $96 billion during July-August on market operations. The Bank of Japan raised rates earlier this month in response to rising inflation pressures, and former BOJ executive director Kazuo Momma earlier in the day flagged the possibility of another hike in October.