"Over the last four years, Secretary Solis has been a critical member of my economic team as we have worked to recover from the worst economic downturn since the Great Depression and strengthen the economy for the middle class," Obama said. "Her efforts have helped train workers for the jobs of the future, protect workers’ health and safety and put millions of Americans back to work."
Solis was a four-term congresswoman representing southern California, and was the first Hispanic woman to serve in the U.S. Cabinet.
Solis becomes the fifth member of the Cabinet to announce that she intends to leave in Obama's second term, joining Secretary of State Hillary Clinton, Secretary of Defense Leon Panetta, Treasury Secretary Timothy Geithner and Environmental Protection Agency Director Lisa Jackson.
Her resignation will likely intensify pressure on the White House to consider diversity in the remainder of its Cabinet appointments. On Wednesday, White House press secretary Jay Carney defended the president's record on diversity, arguing "women are well represented in the president's senior staff here."
"The president believes that diversity is important because having diversity increases the excellence of the pool of advisers around you, pool of the staff that you have here," Carney said. "And I think that's been demonstrated by the — the kinds of — you know, the degree of talent that he has around him now and has had ... around him in the first term. And I think it will be true in the second term."
A White House source confirmed at least one of the women in Obama's Cabinet — Health and Human Services Secretary Kathleen Sebelius — would be returning for the president's second term. Attorney General Eric Holder, an African-American, and Japanese American Secretary of Veterans Affairs Eric Shinseki will also be returning.
It's not clear who the White House will look at to replace Solis, but one possibility is Maria Echaveste, the former deputy chief of staff for former President Clinton. The appointment of AFL-CIO executive vice president Arlene Holt Baker could also be considered as a nod to organized labor.
Solis, in a letter to Labor department employees, said she was proud of the administration's effort to reboot the economy and reduce unemployment.
“Because President Obama took very bold action, millions of Americans are back to work. There is still much to do, but we are well on the road to recovery, and middle class Americans know the president is on their side," Solis wrote.
“Together we have achieved extraordinary things and I am so proud of our work on behalf of the nation’s working families. It has been more than an honor to work alongside you in fulfilling the department’s mission. Working with all of you as the nation’s 25th secretary of labor, I have come to learn that the work we do every day is indeed a labor of love."
— Updated at 5 p.m.