U.S. President Donald Trump's complaints about China's trade practices have increased the odds that a 25-year-old U.S. law that established free trade with Beijing is repealed, trade experts have said, a move that could raise tariffs to 61% on average.

Buried in the barrage of first-day executive orders was an instruction from Trump to his commerce secretary and trade representative to "assess legislative proposals" regarding Permanent Normal Trade Relations (PNTR) with China.

The designation, which generally deters the U.S. government from imposing tariffs on trade partners, was extended to China in 2000, in a major move that opened the floodgates of Chinese exports into the United States.