WASHINGTON

President Donald Trump hit back at China in their mounting trade war, raising existing and planned tariffs in retaliation for Beijing's announcement earlier in the day of new duties on American goods.

Trump slammed the "unfair Trading Relationship," and said "China should not have put new Tariffs on 75 BILLION DOLLARS of United States product (politically motivated!)."

The promised response -- which came in a signature Trump tweetstorm -- said existing 25 percent tariffs on $250 billion in Chinese goods will increase to 30 percent starting October 1.

And tariffs on $300 billion in products, due to take effect September 1 at 10 percent, will now be set at 15 percent, he said.