The United States will increase existing and planned tariffs on Chinese imports in response to Beijing's imposition of new levies on American products, President Donald Trump said Friday.

"China should not have put new Tariffs on 75 BILLION DOLLARS of United States product (politically motivated!). Starting on October 1st, the 250 BILLION DOLLARS of goods and products from China, currently being taxed at 25%, will be taxed at 30%," the president said on Twitter.

"Additionally, the remaining 300 BILLION DOLLARS of goods and products from China, that was being taxed from September 1st at 10%, will now be taxed at 15%," he wrote, signaling the latest in a series of tit-for-tat moves that began in 2018.

Beijing said earlier Friday that it planned to impose new taxes on imports from the US and Trump took to Twitter within hours to vow retaliation.

The president's threat caused a sharp drop on the New York Stock Exchange, where the Dow Jones Industrial Average ended the day down 623 points, or 2.37 percent, at 25,628.90.

In a series of tweets published just hours after learning of Beijing's decision, Trump accused the Asian giant of having "stolen our Intellectual Property at a rate of Hundreds of Billions of Dollars a year."

The president said he won't let the status quo continue.

"We don't need China and, frankly, would be far better off without them. The vast amounts of money made and stolen by China from the United States, year after year, for decades, will and must STOP," he added.

Trump, who has frequently railed against offshoring by US companies, also said American corporations need to move their China-based operations elsewhere.

"Our great American companies are hereby ordered to immediately start looking for an alternative to China, including bringing your companies HOME and making your products in the USA," the president wrote.

Lastly, Trump called on the US's leading shipping service companies - FedEx, Amazon, UPS and the United States Postal Service - to "SEARCH FOR & REFUSE" all deliveries of fentanyl from China or anywhere else in the world.

Fentanyl, a synthetic opioid up to 100 times more potent than morphine, is used in the US to treat moderate-to-severe chronic pain. But its similarity to heroin has made the drug liable to abuse.

"Fentanyl kills 100,000 Americans a year. (Chinese) President Xi (Jinping) said this would stop - it didn't," the president said.

The Centers for Disease Control and Prevention, the US's leading health protection agency, said last month that deaths from drug overdoses in 2018 fell for the first time in nearly three decades.

The CDC put the number of overdose deaths last year at more than 68,000, compared with more than 70,000 in 2017.

Trump threatened on Aug. 1 - after little progress had been made in the latest bilateral talks aimed at ending a more than year-long trade spat - to impose 10 percent tariffs on the remaining $300 billion in Chinese goods that still are not subject to levies.

The White House later eased off, saying on Aug. 13 that it will wait until Dec. 15 to impose 10 percent tariffs on certain mass-consumption products imported from China, including smartphones, laptops, videogames and toys.

Some Chinese products, however, still will be subject to the new 10 percent tariffs starting on Sept. 1, including live animals, dairy products, contact lenses, motorcycle engines and lithium-ion batteries.

Those proposed tariffs would be in addition to 25 percent tariffs on $250 billion worth of Chinese imports that began to be imposed in July of last year.

China, for its part, has retaliated by imposing tariffs of up to 25 percent on roughly $110 billion worth of US goods.

That amount would rise to $185 billion if the latest Chinese tariffs of between 5 percent and 10 percent - which target the US farm and automotive sectors and are due to be implemented either on Sept. 1 or Dec. 15 - go into effect, according to Dezan Shira & Associates, a pan-Asia, professional services firm.

With its latest tariff announcement on Friday, China is set to impose punitive taxes on virtually all US imports. EFE