A Beijing official warns that China will take "drastic measures" if Taiwan moves toward independence.
The statement Wednesday was the latest development in recent months in which China continues to assert its ownership and control of the democratically governed Taiwan, increasing military and diplomatic pressure that has drawn concern among world leaders including those in Washington.
"If separatist forces in Taiwan seeking independence provoke, exert force or even break through any red line, we will have to take drastic measures," said China's Taiwan Affairs Office spokesman Ma Xiaoguang, according to Reuters.
China President Xi Jinping has also recently called for the "reunification" of Taiwan with China either by "peaceful manner" or "firm will."
Taiwan has an unofficial diplomatic relationship with the United States, which under the "One China" policy maintains official diplomatic ties with China.
In addition, the United Nations doesn't recognize Taiwan as an independent country.
Ma said provocation by pro-independence forces and "external intervention" could intensify in coming months, the wire service also reports.
He also referred to the hotspot of the Taiwan Strait, a strategic territory that is part of the South China Sea over which Beijing has recently launched repeated air missions to pressure Taiwan.
"Next year, the Taiwan Strait situation will become more complex and severe," Ma said.