China's launches drills around Taiwan to "severely punish" the island's pro-independence leader, as the U.S. boosts its war footing in Japan to deter Chinese "aggression."

China's military concluded two-day war games around Taiwan in which it held long-range, live-fire drills in the East China Sea, marking an escalation of exercises around the island.

China, Japan and South Korea agreed to jointly respond to U.S. tariffs, a social media account affiliated with Chinese state media said on Monday, an assertion Seoul called "somewhat exaggerated", while Tokyo said there was no such discussion.

The tariffs will be two-tiered. First, there will be a 10% baseline tariff on all countries. Additionally, reciprocal tariffs will be charged on the "worst offenders" of nontariff barriers.

China is seeking to coordinate its response to U.S. tariffs with Japan and South Korea, Chinese state media said.