China’s Vice Premier Liu He and U.S. Treasury Secretary Steven Mnuchin have resumed discussions on trade, in the run up to the meeting between the two nations’ top leaders later this month.

The two spoke by phone on Friday, according to people briefed on the matter, who asked not to be named due to the sensitivity of the topic. The conversation didn’t yield any concrete results, the people said. The Wall Street Journal first reported the phone call Monday.

The discussion followed a call between President Xi Jinping and President Donald Trump two weeks ago, the first publicly disclosed call in six months. The two leaders are scheduled to meet at the Group of 20 nations summit in Argentina, which is scheduled to take place from Nov. 30 to Dec. 1.

U.S.-China talks have made little progress since May, when Trump put a stop to a deal that would have seen China buy more energy and agricultural goods to narrow the trade deficit. In Beijing, Trump’s move was seen as an insult to Xi, who sent Liu, his top economic policy official to Washington for the negotiations, and cemented a view that Trump’s real goal is to thwart China’s rise.

China’s Foreign Ministry didn’t immediately respond to a faxed request for comment on the call.

The two nations have levied several rounds of tariffs on each other’s goods, and tariffs on US$200 billion Chinese imports are due to rise to 25 percent from January in the absence of a breakthrough in negotiations.

In a speech to a Washington think-tank on Friday, Peter Navarro, a White House trade adviser who is one of the most outspoken China hawks in the administration, warned "Wall Street" bankers not to get involved in shuttle diplomacy with Beijing. In a thinly-veiled broadside aimed at Mnuchin and other advocates of a negotiated solution he also said no one but Trump or Robert Lighthizer, the hawkish U.S. Trade representative, should be negotiating with Beijing.

The Trump administration has said that it wants a substantive response to a long list of demands for what it calls "structural" changes in Chinese industrial policy. Trump has rejected a number of deals negotiated by aides such as Mnuchin and Wilbur Ross, the U.S. commerce secretary, that were focused on increased purchases rather than substantive reforms.

--With assistance from Miao Han