The U.S. and China signaled today they may be open to resuming negotiations over trade after days of exchanging retaliatory threats, though Treasury Secretary Steven Mnuchin said Beijing must commit to deeper economic reforms.

“To the extent that China wants to make structural changes, I and the administration are available,” Mnuchin said on Thursday.  “We are not advocating tariffs, We are advocating fair trade.”  Mnuchin dismissed the idea that the U.S. and China are locked in a trade war, and instead described it as a dispute.

President Donald Trump upped the stakes on Thursday by moving forward with plans to impose another 10 percent on $200 billion worth of Chinese imports, which could take effect as early as next month.  China has yet to outline exactly how it will respond to the new tariffs. This came just four days after Washington added 25 percent duties on $34 billion worth of Chinese goods with a promise to bring that up to $50 billion.

“For over a year, the Trump administration has patiently urged China to stop its unfair practices, open its market, and engage in true market competition,” USTR Lighthizer said. “We have been very clear and detailed regarding the specific changes China should undertake.  Unfortunately, China has not changed its behavior – behavior that puts the future of the U.S. economy at risk. Rather than address our legitimate concerns, China has begun to retaliate against U.S. products.  There is no justification for such action,” Lighthizer said.

The U.S. is beginning a roughly two-month process of initiating the new tariffs that could go into effect as early as September, according to senior administration officials who briefed reporters before the announcement.

President Trump has promised to increase the tariffs yet again on another $200 billion in Chinese products, bringing the total to $450 billion, if China retaliates again. The tariffs the U.S. launched this week were aimed at Chinese goods like machinery, tractors and airplane wings, but China hit back on U.S. agricultural  goods with a 25 percent import tax on a wide variety of commodities like grains, oilseeds, meat and produce.

The U.S. Department of Agriculture has pledged to make up for some of those Chinese tariffs by providing government assistance, but farm groups appear fairly united in a desire to see the two countries resolve their differences and end the trade war.