The Japanese currency swung from a small decline to gain as much as 1.4% versus the dollar during morning trading in Tokyo.

The U.S. dollar has weakened sharply against the Japanese yen after President Donald Trump and Japan's finance minister confirmed both sides had intervened in markets.

TOKYO -- The Japanese currency briefly surged to the lower 155 yen range against the US dollar on Monday morning after Japan confirmed joint currency market intervention with the…