BEIJING (REUTERS, AFP) - A United States trade delegation headed by Trade Representative Robert Lighthizer and Treasury Secretary Steven Mnuchin will visit China on March 28-29 for the next round of negotiations, China's commerce ministry said on Thursday (March 21).

In return, Vice-Premier Liu He will travel to Washington in early April for more talks, according to ministry spokesman Gao Feng, as the world's two biggest economies try to hammer out a trade deal to end months of disputes.

The back-to-back trips come as Washington and Beijing battle over the final shape of a trade deal, with American officials demanding profound changes to Chinese industrial policy.

The talks will be the first since US President Donald Trump delayed a March 1 deadline to avert a rise in tariffs on US$200 billion (S$269 billion) worth of Chinese imports to 25 per cent from the current 10 per cent.

Mr Trump warned on Wednesday that the US may leave tariffs on Chinese goods for a "substantial period" to ensure that Beijing complies with any trade agreement, adding to uncertainty over the talks.

Over the last eight months, the United States and China have slapped tariffs on more than $360 billion in two-way goods trade, weighing on the manufacturing sectors in both countries.

On Friday, China's parliament approved a foreign investment law to strengthen protections for intellectual property - a central US grievance - but critics said the Bill was rammed through without sufficient time for input from businesses.

The law was adopted barely three months after a first draft was debated, an unusually quick turnaround for the legislature, which meets once a year.

Unilateral tariffs

Beijing has also expressed willingness to increase purchases of American commodities such as energy and soybeans. But analysts say Chinese officials will be reluctant to accede to demands that could weaken the Communist Party's hold on power - such as fully exposing state enterprises to market forces.

Trump initially said he expected to seal any final bargain at a summit with Chinese President Xi Jinping later this month but that deadline has been pushed back as momentum in the talks has slowed.

US negotiators have insisted that any agreement have teeth - including the ability to impose tariffs unilaterally should China backslide on any commitments to end alleged unfair trade practices.

"We have to make sure that if we do the deal with China, that China lives by the deal," Trump told reporters at the White House Wednesday. He also said the talks with Beijing were "coming along nicely".

Despite Trump's trade wars, the US trade deficit with China last year hit a record, as American consumers drew in foreign-made goods while weakened US sales of agricultural commodities weighed on American exports.