The United States and China escalated the trade war when both parties implemented punitive tariffs of 25% on goods valued at $16 billion.

The last round brings the value of imports subject to tariffs by both countries since the beginning of July to a total of $50 billion. And there are even more tariffs pending. U.S. President Trump had previously threatened to impose duties on nearly all of the $500+ billion in Chinese goods exported annually to the U.S. unless China agrees to certain trade concessions, such as overhauling its intellectual property practices.

The latest U.S. tariffs apply to semiconductors, plastics, chemicals, railway equipment, and more. The U.S. Immigration and Customs Enforcement Service (ICE) confirmed on its website that at 12:01 EDT on Thursday, just after noon in Beijing, it would start collecting additional fees in 279 categories of products imported from China worth $16 billion.

China's list of 333 U.S. product categories subject to duties includes coal, copper scrap, fuel, steel products, buses, and medical equipment. China said its tariffs on $16 billion worth of imports would take effect at 12:01 local time.

The tariffs came into effect in the middle of two days of talks in Washington between mid-level officials on both sides — the first formal negotiations since the U.S. Trade Secretary met with Chinese economic adviser Liu He back in June.

For more on U.S.- China tariffs, visit FOXBusiness and CNBC.