China has "seen hope" in the trade talks with the United States, a senior Chinese trade official said yesterday, stopping short of saying how close both sides are to a deal that will remove additional tariffs slapped on each other's imports.

"The economic and trade teams of both sides are communicating day and night, working on the final text of the agreement," said Vice-Minister of Commerce Wang Shouwen at a press conference on the sidelines of the annual parliamentary meeting.

He emphasised that any trade mechanism contained in the deal must be fair and equal, referring to the US demands for an enforcement process to ensure China complies with its commitments.

The US has accused China of unfair trade and industrial practices, including forced technology transfers, intellectual property thefts, subsidies for its state-owned enterprises and lack of market access.

This has sparked a trade stand-off between the world's two biggest economies since last July, with both countries slapping additional tariffs on each other's imports.

Progress in negotiations has seen Washington suspending further tariff hikes on Chinese imports, and all eyes are on when the leaders of both countries will meet to sign off on a deal.

Mr Wang, who is also China's deputy trade negotiator, noted that the trade dispute has seen American exports to China fall by 7 per cent, while China's import and export trade with the US has plunged by 19.9 per cent in the first two months this year.

"The tit-for-tat tariffs have hurt workers, farmers, exporters and manufacturers. It has damaged investors' confidence and slowed down investment decisions."

But he added that there are ample reasons to be optimistic over a resolution, as both sides have conducted three rounds of high-level talks in the past three months, achieving substantial progress on some important issues.

He noted that the negotiating teams are making full efforts to reach an agreement based on the direction laid out by the leaders of both countries.

"That is, to remove all the tariffs imposed on each other so that bilateral trade relations between China and the US can return to normal."

To illustrate the efforts by both sides to reach a consensus, Mr Wang revealed details of what the negotiators ate and drink.

At the talks in Washington, Chinese Vice-Premier Liu He and US Trade Representative Robert Lighthizer had take-out lunches.

"Vice-Premier Liu had a beef burger and Mr Lighthizer had (a Chinese dish of) eggplant and diced chicken," he said.

"And during the talks, there was coffee and tea. But both of them didn't drink any coffee or tea. They both drank boiled water. This was to find common ground," he added.

Mr Wang said he is hopeful for a win-win deal that is in line with both countries' interests and the world's expectations.

But he did not offer information on whether Chinese President Xi Jinping will go to Mar-a-Largo, Florida, to meet US President Donald Trump later this month.

This week, China's almost 3,000 lawmakers are set to pass a new foreign investment law that bans forced technology transfer by local governments.

Observers have said that the new law was fast-tracked in part to address some of the sticking points in the trade talks with the US.

Mr Wang noted the new law will provide important legal protection for foreign firms and ensure a level playing field for them. It will also ensure foreign firms can transfer funds freely in and out of China when they want to repatriate profits or withdraw their investments.

He is confident that the implementation of the new law will "greatly improve" China's investment environment.

Yesterday, China's state-owned enterprises regulator defended its state-owned companies as "independent market players", when asked at a press conference if they received preferential treatment from the government.

"They self-manage, are responsible for their own profit and loss, face risks themselves, restrain themselves and develop themselves," said Mr Xiao Yaqing, chairman of the Assets Supervision and Administration Commission.

He said Chinese regulation does not stipulate that government subsidies are reserved for state-owned enterprises and not private firms.

But the government is also standardising subsidies to "help create a level playing field and conditions for companies of all sizes, and help to improve the competitiveness of enterprises".