President Donald Trump wants to move ahead with a plan to impose tariffs on $200 billion in Chinese imports as soon as a public-comment period concludes next week, according to six people familiar with the matter.

Companies and members of the public have until Sept. 6 to submit comments on the proposed duties, which cover everything from selfie sticks to semiconductors. The president plans to impose the tariffs once that deadline passes, according to the people familiar with the matter, who spoke on condition of anonymity because the discussions aren’t public. U.S. stocks fell on the news.

Some of the people cautioned that Trump hasn’t made his final decision, and it’s possible the administration may enact the duties in installments. The U.S. has so far imposed levies of $50 billion in Chinese goods, with Beijing retaliating in kind.

It’s also possible the president could announce the tariffs next week, but say they will take effect at a later date. The Trump administration waited about three weeks after announcing in mid-June that it was imposing tariffs on $34 billion of Chinese goods before they were implemented. The next stage of tariffs on $16 billion of goods took hold in August.

The imposition of the $200 billion tranche is the biggest so far and would mark a major escalation in the trade war between the world’s two largest economies and is likely to further unnerve financial markets that have been concerned about the growing tensions.

China has threatened to retaliate by slapping duties on $60 billion of U.S. goods.

Trump’s plan to bring down his biggest hit yet on China comes as two-way trade talks show little signs of progress. Discussions between U.S. and Chinese officials last week in Washington yielded few results, thwarting hopes for a quick deal.