China and the United States are busy conducting in-depth discussions on a phase-one trade agreement, and additional tariff rollbacks are key to signing a deal, China's Ministry of Commerce said on Thursday.

If the two sides reach a preliminary agreement, the degree of tariff removals will fully reflect the importance of the agreement, ministry spokesman Gao Feng said at a weekly briefing.

"The importance of the deal should be measured by both parties," Gao said, adding that the two countries' negotiating teams are holding in-depth consultations on the topic.

Last week, Gao said at a regular briefing that China and the US have agreed to lift additional tariffs on each other's goods step by step if a trade deal is struck. The phase-one deal was outlined by both negotiating teams in early October.

He did not specifically respond to comments from US President Donald Trump on Friday that he had not agreed to remove additional tariffs on Chinese products.

Gao said the trade conflict began because of additional tariffs, so a truce should be reached through tariff elimination, and "this is an important condition for the two sides to reach an agreement".

The General Administration of Customs said on Thursday it was lifting restrictions on the importation of poultry from the US, effective immediately.

The proposal to lift the nearly five-year ban on US poultry imports was announced by the Ministry of Commerce in late October and publication on the customs administration website, which clears imports of all US poultry products, is a formal recognition of the reopening of the trade.

Improving access for US foodstuffs in the Chinese market has been a critical part of Sino-US trade talks. China had banned all US poultry and eggs since January 2015 due to an avian flu outbreak.

Sang Baichuan, director of the Institute of International Business at the University of International Business and Economics, said the misuse of tariffs would lead to wait-and-see attitude toward cooperation between companies from both countries. The cancellation of additional tariffs will benefit China, the US and the rest of the world, Sang said.

Matthew Margulies, vice-president of China operations at the US-China Business Council, said that despite recent frictions, US companies take a long-term view of the relationship and they generally have a positive opinion about opportunities in China.

Margulies said he is optimistic that both sides want to reach an agreement and a phase-one deal will help to stabilize the relationship.

China remains an important market with valuable business opportunities for companies, despite uncertainty due to the ongoing US-China trade dispute, according to the Business Confidence Survey.

However, market access barriers and regulatory obstacles continue to limit their growth potential in the Chinese market, said the survey, which was released on Tuesday by the German Chamber of Commerce in China.

Citing the survey, Gao said two out of three of the surveyed companies intend to further invest in China in the next two years. He said the ministry welcomes suggestions on China's investment environment, and will make continued efforts to relax the restrictions on foreign investment access and increase the protection of legitimate rights and interests of foreign investment.

Contact the writers at jingshuiyu@chinadaily.com.cn