Transportation secretary Elaine Chao will resign, effective Jan. 11, nine days before her term was to expire.
"Yesterday, our country experienced a traumatic and entirely avoidable event as supporters of the president stormed the Capitol building following a rally he addressed," Chao wrote in a three-paragraph statement posted to Twitter Thursday afternoon. "As I am sure is the case with many of you, it has deeply troubled me in a way that I simply cannot set aside."
Chao, who is the wife of Senate Republican leader Mitch McConnell, had been one of only seven of President Trump's original 21 Cabinet or cabinet-level heads to occupy the same post throughout his term.
Secretary of Transportation Elaine Chao.
Her resignation announcement came amid growing calls for Trump's removal from office ahead of the Jan. 20 inauguration of Joe Biden. More than 100 lawmakers, according to NBC, including House Speaker Nancy Pelosi and presumptive Senate Majority Leader Chuck Schumer, have called on Vice President Mike Pence to invoke the 25th Amendment in order to remove the president, a move that would require majority support from the Cabinet.
Chao is the first Cabinet member to announce a resignation since the siege on the Capitol building.
In her tweet, which was addressed to DOT staffers, Chao said she is proud of what they achieved at the department.
"I am hopeful that many of you will carry forward our vision to improve the lives of Americans through this department and beyond," she said.
During her tenure at the department, Chao implemented the Trump administration directive to cut back on regulations, drawing criticism from aviation consumer advocates but praise from airlines.
President-elect Joe Biden has nominated former South Bend, Ind., mayor and Democratic presidential candidate Pete Buttigieg to be secretary of transportation.