The Bank of Japan must be cautious about raising interest rates given the expected hit from U.S. tariffs on the fragile economy, ruling party heavyweight Ken Saito said.

"The BOJ ought to be cautious as everything would be in tatters if its action cools the economy," he said, when asked about market expectations the central bank could hike rates again later this year.

The remark highlights the political pressure the BOJ could face in resuming rate hikes as higher U.S. levies hurt corporate profits and challenge its view that firms will keep hiking pay.