Beijing's commerce ministry announced on October 9 new controls on the export of rare-earth technologies, adding to regulations on a critical industry that has been a key source of tension between Beijing and Washington.

However, just three weeks later, on the same day as talks between Chinese leader Xi Jinping and US President Donald Trump in South Korea, the ministry said it would freeze the measures for one year.

"China will suspend the implementation of the relevant export control measures... for one year, and will study and refine specific plans," an unidentified commerce ministry spokesperson said, adding that the consensus was reached after trade talks in Malaysia this week.

China is the world's leading producer of the minerals used to make magnets that are crucial to the auto, electronics and defence industries.

It has required licences for certain exports of the materials since April, hitting global manufacturing sectors.

Rare earths have been a major sticking point in recent trade negotiations between China and the United States, with Washington accusing Beijing of slow-walking export licence approvals.

The October 9 controls meant exporters would need to have obtained permission for technologies used for rare-earth mining and smelting, among other processing steps.

They also applied to technologies used in the "assembly, adjusting, maintenance, repair and upgrading of production lines", the commerce ministry said.

The United States in turn agreed to suspend for one year a move imposing "Entity List" export restrictions on affiliates of blacklisted foreign companies in which they had at least a 50 percent stake, the ministry said.

It confirmed that the United States agreed to cut tariffs on Chinese goods, including lowering a fentanyl-related tax to 10 percent, and said Beijing would adjust its countermeasures accordingly.

Washington also agreed to suspend for one year its Section 301 investigation into China's shipbuilding industry that led to both sides applying port fees against each other's ships, the spokesperson said.

China would suspend its "countermeasures" on American ships after the US action, also for one year, they said.

Beijing's ministry also said the two leaders had "reached consensus on cooperation in fentanyl trafficking control (and) expanding agricultural trade", without providing further details.

Trump said after the talks that China would be immediately purchasing "tremendous amounts" of US soybeans and other farming products.

The two sides would also resolve issues related to social media app TikTok, the Chinese ministry said.

Washington has sought to wrest the app's US operations from the hands of Chinese parent company ByteDance, citing national security concerns.