Washington (CNN Business) President Donald Trump dealt a blow Friday to investors who were hoping the United States and China were inching closer toward a partial trade deal that would roll back billions in tariffs.

Speaking to reporters, Trump said the US has yet to agree to wiping tariffs, undercutting a statement from China's Commerce Ministry indicating openness to such a concession as part of the first phase of a trade deal between the world's economic superpowers.

"They'd like to have a rollback," the President said. "I haven't agreed to anything. China would like to get somewhat of a rollback, not a complete rollback because they know I won't do it."

The tariffs have been a major sticking point in the negotiations between the two countries, and the latest twist sent stocks falling -- a repeat of earlier episodes in which Trump himself injected uncertainty, even as breakthroughs in negotiations seemed imminent.

It's been almost a year since Trump and Chinese leader Xi Jinping announced an imminent deal after a meeting in Buenos Aires, Argentina. But in the ensuing months, both sides have settled into a tit-for-tat pattern, rattling markets and depressing business investment -- a major drag on the US economy.

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