Chinese officials have warned Japan and South Korea that their relations with Beijing will deteriorate if they allow the United States to base intermediate-range missiles on their soil, several sources said.

One of the warnings came during Chinese Foreign Minister Wang Yi’s separate meetings with his Japanese and South Korean counterparts in August, Japanese and U.S. government sources said.

Beijing’s concerns arose after U.S. President Donald Trump announced that the United States would withdraw from the Intermediate-Range Nuclear Forces (INF) treaty with Russia. One reason cited was that the treaty did not cover China, which was developing such missiles.

With the INF now invalidated, Beijing is concerned that Washington plans to deploy intermediate-range missiles in Japan and South Korea where they would be capable of reaching China.

According to the Japanese and U.S. government sources, China relayed its concerns in bilateral meetings held on the sidelines of the foreign ministers conference between Japan, China and South Korea in Beijing in August.

“If the United States deploys intermediate-range missiles in Japan, that would have a major effect on Japan-China relations,” Wang was quoted as telling then Foreign Minister Taro Kono.

Wang made a similar comment during his meeting with South Korean Foreign Minister Kang Kyung-wha.

According to the sources, Kono did not directly touch upon the possibility of such a U.S. missile deployment in Japan, but he did tell Wang, “Chinese missiles are capable of hitting Japan, so China must first work toward reducing its arsenal.”

Kang told Wang that China should first end its retaliatory measures against South Korea for the deployment of the U.S. military’s Terminal High-Altitude Area Defense system, the sources said.

In October, China again expressed its concerns about the United States deploying intermediate-range missiles in Japan and South Korea.

Randall Schriver, the U.S. assistant secretary of defense for Indo-Pacific security affairs, visited Beijing for meetings with his counterparts who brought up the possible missile deployment.

Schriver subsequently landed in Tokyo where he explained China’s position to high-ranking officials of the Foreign Ministry and Defense Ministry. He described the response from Beijing as interesting.

The United States confirmed with officials in Japan and South Korea that issues between the allies regarding the INF did not have to be discussed with China and Russia.

A Japanese specialist on China said, “After Chinese President Xi Jinping visits Japan next spring, a major issue that will likely arise between Japan and China will be whether Japan allows the United States to base new missiles here.”

A Foreign Ministry source said the official ministry position was that no decision had been made about deploying U.S. intermediate-range missiles in Japan. The source added that it would likely take five years before U.S. missiles would be ready for an actual deployment.

The source also said the government and ruling coalition have not decided on whether the issue of deploying intermediate-range missiles should be put on the Diet agenda for discussions.

However, the United States could push for an early decision. High-ranking officials in charge of foreign affairs and defense from Japan and the United States are scheduled to hold a meeting in December to discuss extended deterrence issues.

The United States plans to hold similar discussions with South Korean officials around the same time.

“Officials will have to begin thinking about various possibilities since the INF issue will have to be dealt with in the short- and medium-term,” a source knowledgeable about Japan-U.S. ties said.