President Trump expressed concerns about the yen's weakness during a recent meeting with Japanese Prime Minister Sanae Takaichi, the country's finance minister said.

Japanese Finance Minister Satsuki Katayama made the comments at a press briefing in Tokyo on Friday.

Earlier this week, Takaichi, who was visiting New York to attend the United Nations General Assembly, held a meeting with Trump to discuss a wide range of topics, including economic security and the economy, among other things.

After the yen weakened to 40-year lows against the dollar in late July, Tokyo and Washington joined forces to intervene in the foreign-exchange market to prop up the yen.

A rate hike by the Bank of Japan and expectations of further rate increases have since lent support to the yen, dimming its appeal as a funding currency for carry trades. But dollar strength and tightening by the Federal Reserve are pressuring the Japanese currency again.

The yen's rebound seems to be built on shaky ground, said Bank J. Safra Sarasin's Claudio Wewel.

BOJ officials' signaling of faster hikes is chipping away at perceptions of the central bank as slow-moving--a view that has long been a drag on the yen, the foreign-exchange strategist said. But recent market reactions show that it may still be too slow relative to other G-10 central banks, Wewel said.

Several other central banks, including some of Japan's regional neighbors, have also turned more hawkish, said Stefan Angrick at Moody's Analytics.

"Against that backdrop, rate hikes from the BoJ won't do quite as much to narrow the gap with the rest of the world as markets may have expected earlier in the year," the economist said.