WASHINGTON 

China's new ambassador to the US said Tuesday that China-US relations face "serious difficulties and challenges” while noting that he aims to enhance bilateral cooperation. 

Earlier in the day, Xie Feng landed at John F. Kennedy International Airport in New York City, where he told reporters that he came here to "safeguard China's interests."

"I'm also the envoy of Chinese people, so I've come here to enhance China-US exchanges and cooperation," he added.

"President Xi Jinping has put forward the three principles of mutual respect, peaceful coexistence and win-win cooperation, which represent the fundamental and right way for the two countries to get along with each other in the new era," he later wrote on Twitter.

"At present, the China-US relationship is faced with serious difficulties and challenges. My appointment means to me not only honor, but also enormous responsibilities. My colleagues and I will carry out our responsibilities and live up to our mission with diligence and fortitude," he added.

"During my posting, I look forward to engaging extensively with the American people from all walks of life, observing and learning about the country at a close distance, and exploring ways to deepen our exchanges and cooperation," Xie wrote.

Xie, 59, is a career diplomat specialized in US-China relations who recently served as vice foreign minister. He succeeds Qin Gang, who left Washington in January to become China’s foreign minister.

The US welcomed Xie’s arrival, with State Department spokesperson Matthew Miller saying that they “look forward to working with the ambassador designate and his team."

“We remain committed, as we’ve said on a number of occasions, to maintaining channels of communication with the PRC to responsibly manage competition,” Miller told reporters during a daily press briefing, referring to the People’s Republic of China, China’s official name.

Relations between Washington and Beijing have been tense in recent months, especially after House Speaker Nancy Pelosi's visit to Taiwan last August and the Chinese spy balloon incident in February, which resulted in Secretary of State Antony Blinken postponing a planned visit to China.

US President Joe Biden on Sunday predicted a “thaw” in relations between the US and China, saying: “And then this silly balloon that was carrying two freight cars’ worth of spying equipment was flying over the United States, and it got shot down, and everything changed in terms of talking to one another. I think you’re going to see that begin to thaw very shortly."

Biden's remarks came at a press conference in Hiroshima, where he went to attend the G-7 leaders’ summit.