China will not hesitate to fight back if the United States escalates its trade spat with Beijing, the commerce ministry said on Thursday, asserting that Chinese President Xi Jinping's pledge to cut import tariffs is not a concession to Washington.

Xi on Tuesday vowed to open China's economy further and lower import duties on goods such as cars. U.S. President Donald Trump responded in a tweet saying he was "thankful" for Xi's kind words on tariffs and access for U.S. automakers, as well as his "enlightenment" on intellectual property issues.

Washington is accusing Chinese firms of stealing the trade secrets of U.S. companies and forcing them into joint ventures to acquire their technology — the crux of Trump's current tariff threats against China.

It would be misleading to say Xi's pledge this week was a concession to the United States, commerce ministry spokesman Gao Feng said at a regular press briefing in Beijing.

Xi was merely outlining China's strategy to open up further, which had nothing to do with its trade friction with the United States, Gao said.