The aftermath. 

Apple Inc. (AAPL) shares were active in pre-market trading Monday following a weekend Tweet from President Donald Trump which warned that consumers would be forced to pay higher prices for its iphones and computers once fresh tariffs on China-made imports were imposed by the White House.

Trump named Apple, as well as U.S. automaker Ford Motor Co. (F) in a series of Tweets Saturday that followed his threat to take the total amount of China-made goods subject to U.S. import tariffs to $517 billion, a figure that would dwarf last year's record $375 billion trade deficit and ignite a potentially damaging trade war with the world's second largest economy. Apple said Friday that the current tariff proposal, which targets $200 billion in China-made goods, could impact pricing for AirPods and the Apple Watch, but did not specifically mention the iPhone in a letter to the U.S. government. 

"Our concern with these tariffs is that the U.S. will be hardest hit, and that will result in lower U.S. growth and competitiveness and higher prices for U.S. consumers," Apple said.

Apple prices may increase because of the massive Tariffs we may be imposing on China - but there is an easy solution where there would be ZERO tax, and indeed a tax incentive. Make your products in the United States instead of China. Start building new plants now. Exciting! #MAGA

— Donald J. Trump (@realDonaldTrump) September 8, 2018

Action Alerts Plus holding Apple shares fell 1.65% to change hands at $217.6 each in the opening minutes of trading, a move that values the Cupertino, Calif.-based group at more than $1.07 trillion.

That said, several stocks in Apple's European and Asia-based supply chain were weaker at the start of trading with Austria-based AMS AG, (AMSSY) which earns an estimated 35% of its revenue from chip sales to Apple, falling 0.37%, Frankfurt-listed Dialog Semiconductor (DLGNF) sliding 2.12% and STMicroelectronics (STM) retreating 1.54% in Amsterdam. 

In overnight Asia trading, suppliers Luxshare Precision Co. Ltd. fell 10% while Lens Technology Co. Ltd. was marked 6.77% lower by the close of trading in Shenzen. Suzhou Dongshan Prevision Manufacturing Co. Ltd. was also marked 10% lower on the CSI 300 index.

Apple CEO Tim Cook addressed the issue of tariffs during the company's third quarter earnings call with investors, describing them as "a tax on the consumer" that winds up "resulting in lower economic growth (that can) sometimes can bring about significant risk of unintended consequences."

A recent analysis from IHS Markit estimated that the factory cost of an iPhone 7, which is assembled in China but uses components from various countries including South Korea, Japan and Taiwan, is about $237, a figure that is then used by U.S. customs officials when they are calculating trade activity with China.

However, the U.S. contribution to the construction of an iPhone is around $69, compared to the China-based contribution of around $8.50, meaning tariffs based on the import of an iPhone would hit both U.S. companies and U.S. consumers harder than they would those in China. 

Cook himself described the public consultation process for the proposed tariffs on $200 billion in China-made goods "tedious" because, he said, "you not only have to analyze the revenue products, which are a bit more straightforward to analyze, but you also have to analyze the purchases that you're making through other companies that are not related to revenue."