Arne Duncan, the U.S. Secretary of Education, has decided to step down from his position in December after a long tenure in which he pushed to make schools across the nation more progressive with the approach to education.

A White House official confirmed Duncan's decision to step down, noting that President Barack Obama named John B. King Jr., the Deputy Secretary of Education, as Duncan's replacement, according to the Washington Post.

Obama is expected to formally make the announcement at 3:30 p.m. today during a press conference.

Duncan has been with Obama since the beginning of his presidency and is one of the few who remain from his original cabinet, according to NPR.

Duncan expressed pride at what his staff accomplished over the past few years despite being smaller than other departments.

"As a comparatively small team, often under challenging conditions and timelines, our staff has continued to offer example after example of dedication beyond the call of duty," he said in an email addressed to his staff, according to the New York Times.

While he was secretary, Duncan led several initiatives such as Race to the Top, the Common Core educational standards and an embrace of charter schools, all of which caused him to come under the line of fire from both the left and right alike.