Chinese enterprises started approaching US suppliers in mid-July to discuss buying agricultural goods including soybeans, cotton, pork and sorghum, commerce ministry spokesman Gao Feng said at a regular press briefing.

Companies "have already purchased some agricultural products," he added.

Beijing and Washington representatives met this week in Shanghai to discuss the tense trade war between the two economies which has seen both sides hit each other with punitive tariffs covering more than $360 billion in two-way trade.

Talks broke down in May after Trump accused Beijing of reneging on its commitments, but the US leader and his Chinese counterpart Xi Jinping agreed to a truce in June.

US President Donald Trump this week said China was supposed to start buying American agricultural goods but had shown "no signs that they are doing so".

Officials at this week's meeting in Shanghai discussed why the earlier negotiations had broken down and made plans for future talks, Gao told reporters.

"This round of consultations was frank, efficient and constructive," he said.

Both sides "will hold intensive consultations in August to properly prepare for the face-to-face meetings of the leaders of the consultations in September," Gao added.