President Donald Trump is readying an announcement on auto levies as soon as Wednesday, according to people familiar with the matter, a move that would escalate his fight with global trading partners ahead of a broader tariff push next week.

The people shared the timing of the expected announcement on condition of anonymity, to discuss plans not yet made public. One of the people, though, cautioned that the president’s plans could still shift.

Trump told reporters earlier this week that he would detail the auto levies in the coming days, indicating they could come before his planned April 2 rollout of sweeping reciprocal tariffs targeting other nations. The president has said the levies will help spur growth in the domestic auto sector and force companies to move more production to the US.

The level and scope of the auto tariffs are not clear, including what, if any, exemptions would be included or considered. It’s also unclear if the tariffs would go into effect immediately or over time.

The levies would nonetheless mark a significant expansion of the president’s trade fight, and likely target some of the biggest automotive brands in countries including Japan, Germany and South Korea, all major US trading partners. The move risks disrupting operations for North American automakers, who rely on highly integrated chains across the US, Mexico and Canada.