China’s Foreign Ministry has fired a warning shot after a senior Japanese official suggested Tokyo should reconsider its ban on nuclear weapons in light of a worsening security environment in the region.

China has likely loaded more than 100 solid-fueled DF-31 intercontinental ballistic missiles into the silo fields near the Mongolian border. US officials said the report did not identify the potential targets of the newly loaded missiles and that the report could be subject to change before being formally submitted to Congress.

The investigation is part of a congressional push to raise a firewall blocking U.S. research from boosting China's military buildup.

Russia and China have conducted 10 joint air patrols with bombers to date, demonstrating their military capabilities.

For more than a decade, Western nuclear analysts have sounded the alarm over a particularly dangerous characteristic of China’s nuclear forces: They often overlap with China’s conventional forces. Should the United States and China ever go to war, a ...