President Donald Trump’s tariffs on aluminum and steel imports are mostly driven by concerns that China is glutting global markets and hurting U.S. manufacturing, a former trade adviser to the White House said.

Matt Ronge, the cofounder and CEO of AstroPad, is also contemplating price hikes. AstroPad makes a range of gadgets for creative workers, including a wireless dongle that turns spare iPads or Macs into secondary computer displays and a combination Apple Pencil tip and iPad screen cover that feel more like writing on paper.

Existing American tariffs already restrict steel and aluminum shipments from China, which is now flooding other markets with its exports instead.

The White House published three separate Executive Orders that imposed blanket tariffs on Canadian, Mexican and Chinese imports. The Executive Orders are all similar in scope, with each having a unique justification for imposing the associated tariffs.

In a drab office in China’s industrial heartland, Andy Xiao frets over the future of his shoe materials business, now straining under sweeping tariffs imposed by Donald Trump. The US president has targeted friend and foe alike since taking office a month ago,

China has told the United States government directly to stop using trade and investments as political weapons, according to an official statement released Saturday by China’s Ministry of Commerce in Beijing.