China said it is ready to impose retaliatory tariffs on $60bn worth of U.S. goods if that happens.
The US comment period on $200 billion of proposed tariffs ended yesterday.
His comments contradict the more diplomatic remarks earlier on Friday from his top economic adviser Larry Kudlow who said talks with Beijing are continuing to try to defuse the conflict, and that he was hopeful that a solution could be found.
Trump has had Beijing in his crosshairs since he took office, and has applied increasing pressure to try to convince it to change its policies, allow more imports and reduce the US$335-billion United States trade deficit with China.More news: Cher coming to St. Louis in 2019
Trump tells reporters on Air Force One that his plans to slaps taxes of up to 25 percent on Chinese imports would depend on the choices made by that country's leaders.
The U.S. and China account for more than a third of Korea's total exports, so this trade spat is a major downside risk to the Korean economy. which already saw its exports slow down from the first quarter's four-point-four percent to zero-point-four percent in the second quarter.
Trump has been locked in a trade dispute with Beijing over China's policy of forcing U.S. companies to hand over trade secrets, as a price of doing business in China. "Things can change rather quickly, so the trade war, if a lot of the threats do materialise, I think things will turn very quickly".
The U.S. imported US$505 billion of Chinese products in 2017, Census Bureau figures show. China is promising to retaliate if the White House moves ahead with the new tariffs.More news: Mac Miller Dead at 26 After Apparent Drug Overdose
The administration could announce the implementation timeline for the $200 billion in tariffs at any time.
United States stocks erased gains after Trump's remarks, with the S&P 500 Index falling by 0.3 percent to the lowest in two weeks by 1:26 p.m.in NY.
'The Chinese aren't paying these tariffs, American families are going to pay these tariffs.
"We are still talking with China on a number of issues", said Kudlow. "We want lower (trade) barriers across the board".More news: Barack Obama Slams Donald Trump In Speech - 'He's Capitalizing On Resentment'