Jan. 27 (UPI) -- President Joe Biden's nominee to be the United States' top ambassador to the United Nations began her confirmation hearing in the Senate on Wednesday, and said she plans to watch China to keep Beijing from using the global body to achieve any authoritarian goals.
Linda Thomas-Greenfield, who was nominated to the post last month, testified before the Senate foreign relations committee.
Thomas-Greenfield worked more than three decades in the State Department, serving in diplomatic posts from Kenya to Pakistan, and was U.S. ambassador to Liberia under former Presidents George W. Bush and Barack Obama between 2008 and 2012.
"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," she said in her opening statement. "Their success depends on our continued withdrawal.
"That will not happen on my watch."
Thomas-Greenfield expected questions about China, as well as Biden's plan to rejoin the Iran nuclear deal.
A native of Louisiana, Thomas-Greenfield has spoken in the past about growing up in the segregated South and how those experiences have shaped her diplomatically.
"Like my mentors, role models, and predecessors, I strongly believe diplomacy is an irreplaceable tool in the work of advancing American interests and building a better world," she told the Senate panel.
"I've learned that effective diplomacy means more than shaking hands and staging photo ops."
Thomas-Greenfield said that as U.N. ambassador, she would use every "diplomatic tool in the toolkit" and take tough and difficult positions, if needed.
"The U.N. is uniquely poised to take on our shared global challenges, from countering terrorism to promoting the rights of women and girls to feeding tens of millions living on the brink of famine," she said.
"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.
"If instead we walk away from the table, and allow others to fill the void, the global community suffers -- and so do American interests."
Several of Biden's Cabinet nominees have received confirmation hearings so far and a few have been confirmed by the full Senate, including Secretary of State Antony Blinken, Treasury Secretary Janet Yellen, Defense Secretary Lloyd Austin III and Director of National Intelligence Avril Haines.
Alejandro Mayorkas, Biden's nominee for Homeland Security secretary, could receive full confirmation on Wednesday.