Tariffs must be cut if China and the United States are to reach an interim agreement on trade, the Asian nation's commerce ministry said, sticking to its stance that some U.S. tariffs must be rolled back for a phase one deal.

"The Chinese side believes that if the two sides reach a phase one deal, tariffs should be lowered accordingly," ministry spokesman Gao Feng told reporters, adding that both sides were maintaining close communication.

On a telephone call last week, China's lead trade negotiator Vice Premier Liu He discussed "core issues of concern" with U.S. Trade representative Robert Lighthizer and U.S. Treasury Secretary Steven Mnuchin.

Completion of a phase one deal between the world's two biggest economies had been initially expected in November, ahead of a new round of U.S. tariffs set to kick in on Dec. 15, covering about $156 billion of Chinese imports.