“I’m ready to go to 500,” he said in an interview with the CNBC channel.
Mr Trump’s comments come before the most recent round of US tariffs has had time to take effect.
Last week, Washington listed $200bn (£150bn) worth of additional Chinese products it intends to place tariffs on as soon as September.
The list named more than 6,000 items including food products, minerals and consumer goods such as handbags, to be subject to a 10% tariff.
It is still under public consultation, to last until the end of August.
The President has also been complaining that a strengthening dollar has been hurting US business.
In a series of tweets he blamed the higher dollar on currency “manipulation” by China and the European Union.
Mr Trump also criticised the US Federal Reserve for raising interest rates.
“The United States should not be penalized because we are doing so well. Tightening now hurts all we have done,” he said in a tweet.