Starting on Tuesday, China "completely prohibits" imports of coal, iron, iron ore, lead and seafood from the Democratic People's Republic of Korea, the Ministry of Commerce and General Administration of Customs said.

The joint announcement on Monday said Beijing issued the ban to fulfill United Nations Security Council Resolution 2371, which targets Pyongyang's intercontinental ballistic missile tests in July.

Observers noted that the ban has gone further than a February statement by the Ministry of Commerce, which responded to an earlier Security Council resolution on the DPRK and announced China's suspension of coal imports from the DPRK for the rest of this year.

China's total imports from the DPRK have seen a drastic drop from March to June, and the country "has strictly abided" by the past Security Council resolutions, General Administration of Customs spokesman Huang Songping said last month.

Zhang Liangui, an expert on Korean studies at the Party School of the Central Committee of the Communist Party of China, said it is natural to see China, a permanent member of the Security Council, honor the resolution in a substantial way after voting for it.

The ban could be viewed as a signal to urge Pyongyang to adjust its policies regarding its nuclear and missile programs, Zhang said.

Wang Junsheng, a researcher of Asia-Pacific studies at the Chinese Academy of Social Sciences, warned that the situation is "entering a bottleneck stage" as there is not enough readiness from either Washington or Pyongyang to tone down their rhetoric and barbs.

Beijing and Washington have remained in contact over the peninsula situation. A phone conversation on Saturday between President Xi Jinping and US President Donald Trump touched on the issue.

Joseph Dunford, chairman of the US Joint Chiefs of Staff, is visiting the Republic of Korea, and his trip also includes Japan and China, the Associated Press reported on Monday.

"We are seeking a peaceful resolution to the crisis," said Dunford, who also met with ROK President Moon Jae-in.

Foreign Ministry spokeswoman Hua Chunying said on Monday that it is hoped all parties concerned consider the constructive proposals made by China.

It further is hoped the parties seek a breakthrough and viable ways to resume dialogue on the issue, Hua said at a daily news conference in Beijing.

Earlier this month, Washington threatened potential retaliatory trade measures against China if the country failed to pressure Pyongyang.

In response, Hua said trade and the Korean Peninsula are two separate issues and the two countries should reinforce cooperation on them. "It's not appropriate to use one issue as a tool to keep pressure on the other issue," Hua said.

In another development, Assistant Foreign Minister Kong Xuanyou has taken a concurrent post of China's special representative on Korean Peninsula affairs, according to Kong's updated profile on the foreign ministry's website.

Kong was to replace Wu Dawei, a former vice-foreign minister who served as the country's top envoy on the peninsula issue since 2010.

Before taking over Wu's job, Kong's areas of responsibility included Asia, treaty and law, boundary and ocean affairs as well as consular affairs.