When the BOJ raised interest rates in January, the U.S. economy was in good shape and financial markets were stable, Ueda said.

"Recently, uncertainty surrounding U.S. policy, particularly that on tariffs, has heightened sharply," he told parliament.

"We will scrutinise developments and their impact on Japan's economy without any pre-conception at each policy meeting."

Ueda said Japan's economy continued to recover moderately with rising wages helping accelerate underlying inflation towards the central bank's 2% target.

With real interest rates extremely low, the BOJ will continue to raise interest rates if the economy and prices move in line with its projections, the central bank chief said.

"But we must be vigilant to the fact uncertainty surrounding each country's trade policy is heightening."

(This story has been refiled to correct the day to Thursday, not Friday, in paragraph 1)