BEIJING (Reuters) - U.S. Ambassador to China Terry Branstad was scheduled to visit Tibet this week, a U.S. embassy spokeswoman said, the first visit to the region by a U.S. ambassador since 2015, amid escalating trade tension between the two countries.

FILE PHOTO: U.S. Ambassador to China Terry Branstad speaks at an event to celebrate the re-introduction of American beef imports to China in Beijing, China June 30, 2017. REUTERS/Mark Schiefelbein/Pool

The visit follows the passing of a law in December that requires the United States to deny visas to Chinese officials in charge of implementing policies that restrict access to Tibet for foreigners, legislation that was denounced by China.

“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,” the spokeswoman said in an emailed statement.

Branstad was traveling to Qinghai province and neighboring Tibet from May 19 to May 25 on a trip that will include official meetings as well as visits to religious and cultural heritage sites, the spokesperson said.

Chinese Foreign Ministry spokesman Lu Kang said the government welcomed Branstad’s visit and he could see for himself the big changes that have taken place there since Tibet was “peacefully liberated” more than six decades ago.

China hopes that Branstad does not take any “prejudices” with him on this trip and goes with an objective attitude so he can reach his own conclusions, Lu told a daily news briefing.

“Especially on the protection and development of Tibetan culture, religion, heritage, and history, I hope that he can respect the facts and draw his own conclusions, instead of being confused and disturbed by hearsay and certain long-standing rumors and smears.”

In December, China criticized the United States for passing the Reciprocal Access to Tibet Act, which seeks to promote access to Tibet for U.S. diplomats and other officials, journalists and other citizens by denying U.S. entry for Chinese officials deemed responsible for restricting access to Tibet.

The U.S. government is required to begin denying visas by the end of this year.

CALL FOR RESTRAINT

China says it is “resolutely opposed” to the U.S. legislation on what China considers an internal affair, and it risked causing “serious harm” to their relations.

The ambassador’s visit comes as tensions have been running high between the two countries over trade. China struck a more aggressive tone in its trade war with the United States on Friday, suggesting a resumption of talks between the world’s two largest economies would be meaningless unless Washington changed course.

On Saturday, the Chinese government’s top diplomat, Wang Yi, told U.S. Secretary of State Mike Pompeo that recent U.S. words and actions had harmed the interests of China and its enterprises, and that Washington should show restraint.

While the Trump administration has taken a tough stance towards China on trade and highlighted security rivalry, it has not acted on congressional calls for it to impose sanctions on China’s former Communist Party chief in Tibet, Chen Quanguo, for the treatment of minority Muslims in the Xinjiang region, where he is party chief.

The State Department said in a March report Chen had replicated in Xinjiang policies similar to those credited with reducing opposition to Chinese rule in Tibet.

Beijing sent troops into remote, mountainous Tibet in 1950 in what it officially terms a peaceful liberation and has ruled there with an iron fist ever since.