U.S. Ambassador to China Terry Branstad is making a rare visit to Tibet this week, the first visit paid by an American envoy since 2015.

“This visit is a chance for the Ambassador to engage with local leaders to raise longstanding concerns about restrictions on religious freedom and the preservation of Tibetan culture and language. He will also learn first-hand about the region’s unique cultural, religious, and ecological significance,” a State Department spokesman said on Sunday.

“The Ambassador welcomes this opportunity to visit the Tibet Autonomous Region, and encourages authorities to provide access to the region to all American citizens,” the spokesman said.

Chinese authorities granted Branstad the special permit required for foreigners to visit the Tibet Autonomous Region.

“We welcome Ambassador Branstad’s visit so that he can see the major changes which took place in Tibet for past 60 years after the peaceful liberation,” Chinese Foreign Ministry spokesman Lu Kang said at a press conference on Monday.

“As for the comments from US embassy, we hope this visit can help them make an unbiased judgment that is fact-based especially on the religion, culture, heritage, and history. We hope he can make his own judgment instead of being misguided by rumors,” said Lu.

The Chinese government has given some unlikely excuses for restricting access to Tibet over the years. Last October, China’s Ambassador to the United States Cui Tiankai claimed his government was worried about foreign visitors having a difficult time with the “tough” climate of the mountainous region.

The U.S. State Department strongly criticizes China’s oppression of Tibetan culture and religion in its annual report on religious freedom, citing the Chinese government’s interference in Tibetan religious traditions, demolition of monasteries, travel restrictions on ethnic Tibetans, and “patriotic re-education” programs for Tibetan nuns and monks.

Ambassador Branstad’s visit to Tibet and the adjacent Qinghai province follows the passage of the Reciprocal Access to Tibet Act in December, a law which obliges the State Department to deny visas to Chinese officials who impede access to Tibet by foreign visitors. Chinese officials denied five out of nine formal requests by American diplomatic personnel to visit Tibet in 2018, including one from Branstad.

Radio Free Asia on Sunday quoted human rights activists who said Beijing’s oppression of Tibetans grew worse in 2018:

On Thursday the Dharamsala, India-based Tibetan Centre for Human Rights and Democracy (TCHRD) issued a report that said the human rights situation in Tibet took a sharp downward turn last year with tightened restrictions on travel by Tibetans and a new campaign against “organized crime” targeting Tibetan civil society and cultural practices.

Calling 2018 a “pivotal year” for human rights in the TAR and other Tibetan areas of China, TCHRD  said that new policies and regulations have led to “an increased restriction on human rights and lives of the Tibetan people.”

A nationwide campaign against “crime” and “black and evil forces” introduced at the beginning of the year resulted in the detention, arrest, and torture of human rights and environmental activists and of ordinary Tibetans promoting the use of the Tibetan language, the rights group said in its report.

“Peaceful dissent of any kind and degree was met with harsh penalties,” TCHRD said.

Two more Tibetans set themselves on fire to protest Chinese oppression in December, bringing the total of self-immolations to 157 since 2009.

Beijing has criticized the Reciprocal Access to Tibet Act as unfair American interference in China’s internal affairs. Some members of the U.S. Congress want to go even further by imposing heavy sanctions on specific Chinese officials for their actions in Tibet and other heavily oppressed regions such as Xinjiang province, home of the Uighur Muslims.