BEIJING (Reuters) - China stepped up its warning to Botswana on Wednesday over a planned visit by exiled Tibetan spiritual leader the Dalai Lama next month, demanding the African nation respect China’s core interests.

FILE PHOTO: The Dalai Lama waves as he leaves after speaking on "Embracing the Beauty of Diversity in our World" to thousands at the UC San Diego campus in San Diego, California, U.S. June 16, 2017. REUTERS/ Mike Blake

The Dalai Lama, reviled by Beijing as a dangerous separatist, is expected to address a human rights conference in the capital, Gaborone, on Aug. 17-19 and will also meet Botswana’s president. China is a major investor in Botswana’s economy.

China has already “clearly” expressed its point of view about the Dalai Lama’s visit, Foreign Ministry spokesman Lu Kang told a daily news briefing.

“Issues relating to Tibet concern China’s sovereignty and territory integrity. We demand the relevant country earnestly respect China’s core interests and make the correct political decision on this matter,” Lu said, using stronger language than before on the issue.

“China will not interfere in other countries’ internal affairs, but will certainly not tolerate another country doing anything that harms China’s core interests,” he added, without elaborating.

The Dalai Lama, who fled from Tibet into exile in India in 1959 following a failed uprising against Chinese rule, has long been at loggerheads with China, which sent its troops into Tibet in 1950.

The Dalai Lama, who won the Nobel Peace Prize in 1989, denies he is seeking independence for his Himalayan homeland. He says he is merely seeking greater rights, including religious freedom and genuine autonomy.

Visits by the Dalai Lama to foreign countries infuriate China.

It often retaliates by stopping high-level meetings or taking economic steps, like last year when it imposed new border fees following a visit by the Dalai Lama to Mongolia.

Botswana’s neighbor, South Africa, has denied a visa to the Buddhist monk three times since 2009 in what opposition parties there, and Archbishop Desmond Tutu, say shows the extent of Beijing’s influence over Pretoria.

China’s fast-growing demand for raw materials has made it one of the biggest investors in Africa and its largest trade partner. Chinese state-owned companies have been awarded contracts to build roads, dams, power stations and airports in Botswana.