US Secretary of State Marco Rubio announced on Tuesday that Riley Barnes, the assistant secretary of state for democracy, human rights and labour, would serve as US special coordinator for Tibetan issues.

Rubio named Barnes in a statement marking Losar, the Tibetan new year, while reiterating Washington's commitment to supporting Tibetan rights, language and religious heritage.

China's foreign ministry accused the United States on Wednesday of "using Tibet-related issues to interfere in China's internal affairs".

"The US's establishment of the so-called 'special coordinator for Tibetan issues' interferes with China's internal affairs, and China has never recognised it," it said in a statement.

"Tibet affairs are China's internal affairs and tolerate no interference from any external forces," it added.

US policymakers have sought in recent years to defend Tibetan religious rituals of selecting the Buddhist spiritual leader, the Dalai Lama.

The current Dalai Lama, who Beijing condemns as a separatist, has lived in exile in India since fleeing the Tibetan capital Lhasa after Chinese troops crushed an uprising in 1959.

Critics fear that China will seek to identify and groom a compliant successor to the charismatic 90-year-old, who has used his global stature to advocate greater rights for Tibetans.

The US special coordinator position is required by an act of Congress passed in 2002.

Successive administrations have designated senior officials to serve concurrently in the role, although President Donald Trump in his first term waited months before making an appointment.

As a senator, Rubio was known for his staunch advocacy of human rights in China, leading an effort to support the Uyghur minority with a law that banned imports from the Xinjiang region unless they were certified not to involve forced labour.

Since becoming the top US diplomat, Rubio has joined the Trump administration in narrowing the focus on human rights, using the issue as a cudgel against adversaries while mostly refraining from criticising Trump's partners.