The stock market is waiting anxiously for the next move on tariffs as China’s retaliation to levies from the U.S. has put markets on edge amid fears of an escalating tit-for-tat trade war between the two powers.

Wall Street was on track to a cautious opening on Tuesday as investor appetite for risk waned after China retaliated against new trade restrictions announced by U.S. President Donald Trump with counter tariffs.

The U.S. Postal Service’s decision may block or delay parcels from retailers including Shein and Temu from entering the United States.