China will make careful evaluations and respond accordingly if the United States unveils a detailed plan on the proposed border-adjustment tax, Commerce Minister Gao Hucheng said Tuesday.

China is aware of a recent proposal within the U.S. administration concerning a border tax on imports, said Gao at a press conference when answering a question on U.S. President Donald Trump's posts on Twitter.

All countries should abide by international trade rules when formulating trade policies, the minister said.

He said China does not want to comment on remarks made by U.S. presidential candidates during the election campaign, instead it would rather focus on the new administration's attitude toward trade ties with China.

Speaking of the Regional Comprehensive Economic Partnership (RCEP), Gao said there has been substantial progress in negotiation, but there were still some difficulties to be solved.

China will continue to play a constructive and positive role in the negotiation and make joint efforts with all parties to reach agreements on the remaining issues and conclude the RCEP talks at an early date, he said.

Launched in November 2012, the RCEP talks involve ASEAN and its six major trading partners -- China, Japan, the Republic of Korea, India, New Zealand and Australia -- with an aim of facilitating expansion of regional trade and investment.