The chief of Japan's auto lobby warned that the potential April 2 start of auto tariffs proposed by U.S. President Donald Trump could force automakers and suppliers to make significant adjustments to their production schedules.

U.S. President Donald Trump's proposed tariff hike on vehicle imports from April will likely lead to fewer Japanese exports and reduced domestic production, the head of the country's auto industry body said Wednesday.

Business sentiment among Japanese manufacturers in March worsened for the first time in three months into negative territory on concerns about U.S. tariff policies and weakness in China's economy, a Reuters Tankan poll found.

The BOJ's decision comes just ahead of the U.S. Federal Reserve's policy meeting, where the central bank is expected to keep its benchmark interest rate steady.