UNITED NATIONS (NewsNation Now) — If confirmed by the U.S. Senate as America’s ambassador to the United Nations, Linda Thomas-Greenfield pledges she will vigorously counter China’s authoritarian agenda and engage in “people-to-people diplomacy.”

The veteran foreign service officer is due to appear before the Senate Foreign Relations Committee for her confirmation hearing on Wednesday.

In prepared remarks, Thomas-Greenfield will stress the importance of U.S. re-engagement with the 193-member world body in order to challenge efforts by China to make diplomatic inroads as the outspoken major player on the global stage. Beijing has been pushing for greater multilateral influence in a challenge to traditional U.S. leadership.

“We know China is working across the U.N. system to drive an authoritarian agenda that stands in opposition to the founding values of the institution – American values,” Thomas-Greenfield will say, according to excerpts from her statement.

“Their success depends on our continued withdrawal. That will not happen on my watch,” she will say.

Thomas-Greenfield says she also will back reforms that make the U.N. “efficient and effective” and promises to develop “a strong partnership” with the Senate Foreign Relations Committee.

A 35-year veteran of the U.S. Foreign Service, Thomas-Greenfield has served on four continents, most notably in Africa and is the most experienced diplomat of the six people named by President Biden for top national security positions.

“Throughout my career, from Jamaica to Nigeria, Pakistan to Switzerland, I’ve learned that effective diplomacy means more than shaking hands and staging photo ops,” Thomas-Greenfield says in her prepared remarks.

“It means developing real, robust relationships,” she says. “It means finding common ground and managing points of differentiation. It means doing genuine, old-fashioned, people-to-people diplomacy.”

Former President Donald Trump had announced plans to quit the World Health Organization, and pulled out of the U.N. Human Rights Council, the U.N. cultural agency UNESCO, a global climate change accord and the Iran nuclear deal.

The Trump administration cited the WHO’s inadequate response to the initial outbreak of the coronavirus in China’s Wuhan province late last year and the lack of reforms requested by the administration as reason to initiate withdrawal from the global health organization. The U.S. is the agency’s largest donor.

On his first day in office last week, Biden rescinded the U.S. decision to withdraw from the WHO and announced a return to the climate agreement.

“When America shows up, when we are consistent and persistent, when we exert our influence in accordance with our values, the United Nations can be an indispensable institution for advancing peace, security, and our collective well-being,” Thomas-Greenfield will say.

“If instead we walk away from the table, and allow others to fill the void, the global community suffers — and so do American interests,” she will say.

Beijing also has come under sharp criticism from the U.S. and many other nations for its treatment of more than 1 million Uighurs and members of other Chinese Muslim minority groups and for its delayed announcement of COVID-19, which was first diagnosed Wuhan.

The Associated Press and Reuters contributed to this article: Reporting by Edith M. Lederer/AP and Michelle Nichols/Reuters.