Hong Kong (CNN Business) Asian stocks and the Chinese yuan took a beating Friday after US President Donald Trump announced another round of tariffs on China.

Suppliers of the Chinese tech company Huawei were hit particularly hard after Trump reignited his country's trade war with China by saying he would add a 10% tariff on $300 billion worth of Chinese-made products in September — effectively taxing all goods from China that come into the United States.

Smartphone component manufacturer Sunny Optical Technology plummeted 6%, while AAC Technologies also tumbled 5%. Q Technology lost 8%, and BYD Electronic sank 7.9%.

All of those stocks are listed on Hong Kong's, which fell 2.4% by noon on Friday.

The Chinese yuan tumbled against the dollar, both in Shanghai and in the offshore market where it moves more freely.

In trading outside of China, one US dollar now buys about 6.9606 yuan. Earlier Friday, the yuan fell to as low as 6.9786 — the weakest this year.

In mainland China, where the yuan fluctuates around a reference rate set daily by the People's Bank of China, the currency stands at 6.9355 to the dollar.

Trump's announcement — made in a series of tweets overnight — came just after US trade representatives returned from a round of negotiations in Shanghai. While both sides agreed those talks were "constructive," they announced no tangible progress

China slammed Trump's tariff news Friday.

Adding tariffs "is not a constructive way to resolve the trade dispute, it's not the correct way," Foreign Minister Wang Yi said in response to a question shouted by local government-run station Shenzen TV. Wang was attending a meeting in Bangkok, Thailand.

Earlier this week, the US-China trade talks ended in Shanghai with little sign of progress. Even so, both sides said discussions were "constructive" and agreed to meet in September.

Rare earth stocks in Asia soared Friday — one of the market's few winners. Beijing has previously implied that it might halt exports of rare earth elements to the United States as its next bargaining chip in the trade war. China controls more than 90% of rare earths production, which is key to the production of smartphones and tablets, according to the US Geological Survey.

And China's new Nasdaq-style board in Shanghai rallied. All 25 of those stocks rose by early afternoon.

"Markets are reeling after President Trump expressed his frustration with China's stalling techniques," wrote Stephen Innes, managing partner for Vanguard Markets Pte in Singapore, in a research note Friday.