Taiwan leader Tsai Ing-wen should not misjudge the situation and take the island to a dangerous place, a Chinese mainland spokesman warned on Thursday after Tsai, who was reelected on Saturday, described it as an "independent country" in a recent interview.

Taiwan has never been a country and is a sacred and inalienable part of China, said Ma Xiaoguang, a spokesman for the State Council's Taiwan Affairs Office.

"Anyone who dares to challenge this hard fact is doomed to failure and will bring ruin upon themselves," he said.

Ma warned Tsai and the island's ruling Democratic Progressive Party not to get carried away and misjudge the situation to create more tension across the Taiwan Straits, which would lead the island to a dangerous place.

Commenting on cross-Straits relations in a recent interview with the British Broadcasting Corporation, Tsai said Taiwan is already "an independent country".

Ma said: "The mainland's resolve to safeguard the country's sovereignty and territorial integrity is as firm as a rock. We will never allow anyone, any organization or any political party to separate any piece of territory from the country at any time or in any form."