China's defence ministry said on Thursday that Japan will have to pay a "painful price" if it steps out of line over Taiwan, responding to Japanese plans to deploy missiles on an island some 100 km (62 miles) from Taiwan's coast.

The remarks come amid the two countries’ worst diplomatic crisis in years, after the Japanese prime minister said a Chinese attack on Taiwan could trigger a military response from Tokyo.

President Trump spoke with Chinese leader Xi Jinping this week, and the Chinese government said Xi outlined what it called China’s "principled" position on Taiwan. The self-governing democracy of 23 million has never been part of Communist China,

Taiwan Premier Cho Jung-tai said on Tuesday that a "return" to China is not an option for the island's 23 million people, after Chinese President Xi Jinping pressed his country's sovereignty claims in a call with U.

President Donald Trump reportedly called the new prime minister of Japan, Sanae Takaichi, and asked her to back off public statements of support for Taiwan following a long, “angry” call with China’s President Xi Jinping,

That role also means a war over Taiwan could be "cataclysmic," the report warned, potentially "wiping out as much as 10 percent of global GDP"—an unprecedented economic hit in modern times. The authors said the ramifications of such a scenario could be "on par with the 2008 Global Financial Crisis."

China may conquer Taiwan through energy blockade and gray-zone tactics rather than military invasion, new defense study reveals. Beijing's strategy targets fuel imports.

China on Friday urged Japan to confront its colonial rule over Taiwan and withdraw recent comments by Japanese Prime Minister Sanae Takaichi that Beijing says interfere in its internal affairs.