In Taiwan, camera lens-maker Largan Precision slid nearly 8 percent, Foxconn, formally known as Hon Hai Precision Industry, fell 3.4 percent, while assembler Pegatron dropped nearly 4 percent.
Taiwan's ASE Technology, which counts Apple as one of its top clients, fell 2.9 percent.
Chien Bor-yi, an analyst at Taipei-based Cathay Futures Consultant, said Apple's component supply chain in Taiwan would take a major hit if the United States increased tariffs on Chinese imported products.
"People have concerns about the stock market. It's not a seller's market, but it's also not a buyer's market. No one knows how deep the well is," he said.
The technology sector is one of the biggest potential losers in the $200 billion tariff list proposed by Washington on Chinese imports because the tariffs would make imported computer parts more expensive.
Trump warned on Friday that he was ready to slap tariffs on virtually all Chinese imports into the United States, threatening duties on a further $267 billion of goods.
Hong Kong-listed AAC Technologies fell more than 5 percent. The company supplies acoustic components and haptic technology — which enables users to receive tactile sensations from an interface — for Apple products such as the iPhone, iPad and Apple Watch.
In Japan, Nissha eased 0.4 percent, Japan Display fell 0.7 percent and Sharp dropped nearly 1 percent.
"People are in a bit of a panic today. Looking forward, the focus would be on how the market reacts after Apple releases its latest models," said Kevin Chung, analyst at JihSun Securities Investment Consulting.