In this June 29, 2015 file photo, exiled Tibetan spiritual leader Dalai Lama delivers a speech at the ESS Stadium in Aldershot, southern England. AP

NEW YORK, United States—The Dalai Lama on Friday canceled a US trip next month after doctors advised him to rest, a decision sure to heighten concerns among the 80-year-old Tibetan leader’s supporters.

The exiled Buddhist leader visited doctors in the United States who “advised His Holiness to rest for the next several weeks,” a statement from his office said.

“As a result, His Holiness’ planned October US visit has been canceled,” the statement said, apologizing to all involved in organizing the trip.

The Dalai Lama had scheduled several stops, including Philadelphia, where he was to receive the Liberty Medal in recognition of his advocacy of human rights.

READ: Dalai Lama celebrates 80th birthday with California summit

Despite his age, the Dalai Lama maintains a rigorous travel schedule. He recently wrapped up a visit to Britain and in July celebrated his 80th birthday among supporters in California.

The Nobel laureate has appeared to be in good health in recent years, although in 2002 he was hospitalized in Mumbai for an infection.

The Dalai Lama fled Tibet for exile in India in 1959 amid an abortive uprising against China’s iron-fisted rule.

READ: Tibet after the Dalai Lama

His spiritual teachings have won him a global following but he remains shunned by China, which has tried to ostracize leaders and artists who deal with the monk.

China has widely been seen as waiting for the Dalai Lama’s death, believing that the movement for Tibetan rights would not survive without its charismatic and globally famous leader.

The Dalai Lama, an avowed pacifist, says that he recognizes China’s rule over Tibet and is seeking greater freedoms.

China insists that the Dalai Lama is nonetheless a “splittist,” and some younger Tibetan activists in exile have advocated a more militant approach.

As his age advances, the Dalai Lama has given up his political role and instead delegated to an elected government in Dharamshala, India, voted by exiled Tibetans.

The Dalai Lama has also increasingly spoken of succession and has not ruled out picking his reincarnation before his death, fearing that China would instead pick its own boy whom it would use to advance its agenda.

His stance has led the Chinese communist rulers, who are officially atheist, to insist that the Dalai Lama can only reincarnate after his death.