ABOARD AIR FORCE ONE/WASHINGTON (Reuters) – US President Donald Trump warned on Friday he was ready to slap tariffs on virtually all Chinese imports into the United States, threatening duties on another $267 billion of goods on top of $200 billion in imports primed for levies in coming days.

The moves would sharply escalate Trump’s trade war with Beijing over his demands for major changes in economic, trade and technology policy. China has threatened retaliation, which could include action against US companies operating there.

Hours after a public comment period closed on his $200 billion China tariff list, Trump told reporters aboard Air Force One that he was “being strong on China because I have to be.”

“The $200 billion we are talking about could take place very soon depending on what happens with them. To a certain extent it’s going to be up to China,” Trump said. “And I hate to say this, but behind that is another $267 billion ready to go on short notice if I want. That totally changes the equation.”

Stock prices slipped after his comments, with the S&P 500 off 0.2 percent, while China’s off-shore trade yuan currency fell against the dollar.

Trump has already imposed 25 percent tariffs on $50 billion worth of Chinese goods, mostly industrial machinery and intermediate electronics parts, including semiconductors.

The $200 billion list, which includes some consumer products such as cameras and recording devices, luggage, handbags, tires and vacuum cleaners, would be subject to tariffs of 10 percent to 25 percent.

Cell phones, the biggest US import from China, have so far been spared, but would be engulfed if Trump activates the $267 billion tariff list.

Trump’s threatened tariffs, now totaling $517 billion in Chinese goods, would exceed the $505 billion in goods imported from China last year. But 2018 imports from China through July were up nearly 9 percent over the same period of 2017, according to US Census Bureau data.