China’s new ambassador to the U.S. arrives amid heightened tensions between the two nations.

China’s new ambassador to the United States arrived in Washington on Wednesday — Qin Gang, a diplomat whose record of vigorously contesting Western criticism suggests that Beijing is steeling for extended tensions with Washington.

In his new role, Mr. Qin will be at the front of efforts by China’s top leader, Xi Jinping, to reshape Beijing’s relationship with Washington, which has spiraled to its lowest point in decades. Beijing sees the Biden administration as continuing to challenge China’s rise, and Mr. Qin will be navigating an increasingly thorny and politically charged relationship.

Chinese diplomats have furiously denounced Washington’s sanctions over Mr. Xi’s hard-line policies in the far western region of Xinjiang and the city of Hong Kong. But they are also trying to find common ground on international challenges like limiting global warming.

Mr. Qin will most likely convey to Washington that Mr. Xi expects his country to be treated as a great power, reflecting a confidence that stems in part from China’s success in controlling the coronavirus epidemic. In a message on the Chinese Embassy’s website, Mr. Qin said that both countries should “treat each other with mutual respect and equality, and pursue peaceful coexistence and win-win cooperation.”

Unlike nearly all of China’s ambassadors to Washington since the 1980s, Mr. Qin has never specialized in dealing with the United States, nor been posted there previously. But as the head of the information office of the Chinese Foreign Ministry, and later the chief of protocol, Mr. Qin appears to have won the trust of Mr. Xi, who has sought to position Beijing as an increasingly powerful counterweight to an international order dominated by the United States.

“For the last 20 years you’ve had a string of America experts posted to Washington,” said Drew Thompson, a former Pentagon official responsible for China. “Somebody whose career has been staked more on upholding the dignity and equal treatment of Chinese senior leaders will come to the job potentially with a different mind-set.”