TOKYO (Kyodo) -- The U.S. government's plan to impose an additional 25 percent tariff on auto imports will have an "extremely large impact" on the Japanese economy, Prime Minister Shigeru Ishiba warned Friday, as exports are a major driver of the Asian country's growth.

Ishiba said during a parliamentary session, "We will think about the most effective means to make the United States understand that this will not be of benefit to it," while expressing readiness to continue negotiations with Washington.

Bank of Japan policy board members also voiced concern about the negative impact of the tariffs on the nation's economy, a summary of opinions from a March policy meeting showed Friday, at a time when it has become inclined to lift interest rates to curb inflation.

The central bank "will need to be particularly cautious when considering the timing for raising the policy interest rate" since tariffs pursued by U.S. President Donlad trump could hurt Japan's economy, one member was quoted as saying.

Another member said, "Downside risks to Japan's economy have increased," arguing that the bank should keep the policy rate at its current level for the time being, according to the BOJ.

At its two-day meeting held last week, the BOJ maintained its key short-term interest rate at 0.5 percent, citing heightened uncertainty about U.S. trade policy. Governor Kazuo Ueda said the bank will tighten monetary policy further if conditions are met.

But at least one member remained concerned about inflation, quoted as saying that a dim economic outlook does not mean the BOJ "should always conduct monetary policy in a cautious manner" and the central bank "may face a situation where it should act decisively."