Deputy Secretary of State Wendy Sherman is expected to depart her post this summer, three sources familiar with the matter told CNN.

The announcement of her departure is expected in the coming days, two of the sources said.

Sherman has been a central player at the department throughout the Biden administration. She has focused on key foreign policy objectives and challenges, including the US-China relationship.

Sherman often took on some of the tougher diplomatic duties. In February, Sherman and Secretary Antony Blinken summoned China's top official in Washington to the State Department and delivered "a very clear and stark message" about the discovery of a Chinese surveillance balloon, officials told CNN at the time.

Her replacement is unknown at this time, the sources said.

The Senate confirmed Sherman as deputy secretary of State in April 2021. She was the first woman to hold the position.

"She leaves incredibly big shoes to fill," said one of the US officials familiar with the matter.

Sherman also came into the role with deep foreign policy expertise, having served as the chief negotiator with Iran, which led to the Iran nuclear deal during the Obama administration. In addition to covering many other consequential portfolios, she was a key player on North Korea policy during the Clinton administration.

The expected change comes as the department is facing other personnel movements. The administration is preparing to nominate James O'Brien as the assistant secretary for European affairs. O'Brien is currently serving as the top sanctions official at the department, playing a central role in developing the sanctions regime targeting Russia after the country invaded Ukraine last year.

The State Department did not immediately respond to a request for comment.