Foreign Ministry spokesman Lu Kang said on Monday that equality is a must in reaching a trade deal with the United States.

US President Donald Trump said on Monday in Japan that Washington isn't ready to strike a trade deal with China, but he's leaving open the possibility that the two nations could reach an agreement someday.

He predicted a "very good deal with China sometime into the future, because I don't believe that China can continue to pay these really hundreds of billions of dollars in tariffs".

The US has made various remarks about trade negotiations, with some saying the agreement will come out soon while others are saying it's still difficult to reach an agreement, Lu said at a regular news conference on Monday.

China's position has been consistent, Lu said. "The trade friction should be resolved through friendly consultations and negotiations, which must be based on mutual respect, equality and mutual benefit," he added.

The two countries are in a tense standoff over trade. They started tariff exchanges in July, when the United States' first round of tariffs on $34 billion worth of Chinese goods took effect. Washington threatened to further escalate the trade dispute and has increased tension by placing restrictions on Chinese companies, such as Huawei Technologies Co.

Huang Yiping, deputy dean and professor of the National School of Development at Peking University, said two parties normally strive to reach a win-win resolution in trade consultations. But the US government is different, because it wants to ensure only it gains advantages from trade negotiations, Huang said.

It reflects that the US government is, to some extent, "unreasonable" in talks with China, Huang said recently at a seminar in Beijing. Against such a backdrop, Huang said it's difficult to predict whether the two countries can reach a deal.

Wei Jianguo, a former vice-minister of commerce, said the US government's frequent accusations against China have negated the possibility of a deal. "The US hasn't realized China's steadfast determination to defend its national interests. It is impossible to enforce a one-sided deal," said Wei, vice-president of the China Center for International Economic Exchanges, a think tank in Beijing.

Zhang Yansheng, a senior researcher at the China Center for International Economic Exchanges, said the US government has been making unexpected, often contradictory, comments or moves.

Zhang cited that the US government used to say that if China-US negotiations broke down, a 25 percent additional tariff would be imposed on Chinese imports. "But why did Washington raise tariffs while the 11th round of negotiations was underway? An explanation is needed."

Cao Desheng contributed to this story.