China's only aircraft carrier has entered the Taiwan Strait, the island's defence ministry said Wednesday, seen as a show of strength by Beijing as tensions rise between the two sides.
The Liaoning has not entered Taiwanese waters but has gone into an area covered by its air defence zone, according to the ministry.
Taiwanese media said the island's military had dispatched F-16 fighter jets and other aircraft Tuesday night to monitor the Chinese carrier group. The defence ministry would not confirm those reports.
"The military is monitoring the whole situation and will act as necessary. We urge Taiwan's people to be at ease," the defense ministry said in the statement.
It comes just after Taiwan's President Tsai Ing-wen visited the United States at the weekend on a transit to Central America, despite protests from Beijing.
China, which considers Taiwan a breakaway province to be brought back within its fold, was incensed by an unprecedented call between Tsai and Donald Trump last month and has since stepped up military drills near the island.
Although they do not have official relations, the United States is Taiwan's most powerful ally and main arms supplier.
The Liaoning has been carrying out its first exercise in the Pacific and already passed south of Taiwan last month.
It entered the southwest of Taiwan's air defence identification zone (ADIZ) at 07:00 Wednesday local time (23:00 GMT), the defence ministry said, along with escort vessels.
"(It) is sailing west of the midline of the Taiwan Strait, moving north," the ministry said in a statement.
Experts have said the showing of the second-hand, Soviet-built Liaoning is "symbolic" rather than a pose of any real threat compared with the military might of the US.
Tsai stopped in Houston Saturday and met with Republican Senator Ted Cruz during her stay, which was slammed by Beijing as an attempt to "undermine China-US relations."
She is this week visiting Honduras, Nicaragua, Guatemala, and El Salvador -- among the dwindling number of states that have formal diplomatic relations with Taiwan.
While the focus of her visit is to bolster ties with allies, her US stopovers are being closely watched with speculation she may make contact with US President-elect Trump and his team.