US President Donald Trump said on Thursday that the United States was in talks with China on tariffs, adding that he was confident the world's largest economies could make a deal to end a bitter trade war.

"Yeah, we're talking to China," Trump told reporters in the Oval Office.

Trump said that the talks had happened since he upped tariffs on China to a whopping 145 percent, after Beijing retaliated to his sweeping worldwide levies.

But Trump was cagey when asked whether he had spoken directly with President Xi Jinping, despite having dropped several hints in the past that he has.

"I've never said whether or not they've happened," he said when asked about talks with Xi. "It's just not appropriate."

Trump's administration is locked in a war of sky-high reciprocal tariffs with China that has unnerved world markets. (AFP)