President Donald Trump told reporters Thursday that tariffs on China could be raised by another $300 billion if necessary.
"Our talks with China, a lot of interesting things are happening. We'll see what happens," Trump said, according to Reuters, without giving details on what goods could be targeted. "I could go up another at least $300 billion and I'll do that at the right time."
"But I think China wants to make a deal and I think Mexico wants to make a deal badly," he said at Ireland's Shannon Airport on his way to France for the 75th anniversary of the D-Day invasion.
Negotiations between Beijing and the Trump administration took a turn for the worse in early May with the increase of tariffs on $200 billion worth of Chinese goods exported to the U.S., and an effective ban on American companies doing business with Chinese telecom giant Huawei.
Beijing responded with tariffs on $60 billion worth of U.S. goods, the announcement of an "unreliable entities list" and a far tougher stance against U.S. requests.
In July, Trump indicated he was willing to slap tariffs on every Chinese product imported in the U.S. should the need arise. "I'm ready to go to 500," the president told CNBC.
IMF warning
Market sentiment has soured amid the trade tensions, with new threats also directed toward Mexico. Trump wants to impose a 5% tariff on all Mexican imports starting Monday if Mexico doesn't take unspecified steps to control the migrant flow into the United States. The threat has been criticized even by members of his own party.
On Wednesday, the International Monetary Fund said U.S.-China tariffs that have been implemented and proposed could cut global economic output by 0.5% in 2020.
Christine Lagarde, the IMF's managing director, said in a briefing note that taxing all trade between the world's two largest economies would cause some $455 billion in gross domestic product to evaporate. This would be a loss larger than South Africa's economy, the note said.
—CNBC's Evelyn Cheng contributed to this article.