Chinese leader Xi Jinping has made a rare trip to Tibet and hailed the crushing of “separatism” in the once-restive region, as Beijing prepares for a looming struggle over the successor of the aging and exiled Dalai Lama and the hearts and minds of millions of Tibetans.

A power struggle is taking shape over choosing a successor to the 90-year-old Buddhist leader. In a trip to Tibet’s capital, China’s leader emphasized maintaining Beijing’s control.

President Xi Jinping urged unity on a surprise visit to Tibet, appearing before 20,000 people to mark 60 years since China created the autonomous region after annexing it.