Two senior Obama aides to depart the White House

As President Obama begins his final two years in office, two of his top aides are preparing to depart his administration.

White House communications director Jennifer Palmieri will leave her post within 30 to 45 days, CBS News senior White House correspondent Bill Plante reports. Palmieri, who left a senior post at the Center for American Progress in 2011 to join the administration, is expected to assume a senior communications role in the still-undeclared presidential campaign of former Secretary of State Hillary Clinton.

And Dan Pfeiffer, a senior adviser to the president and one of his longest-serving aides, will leave the administration in March, the White House announced Wednesday.

Pfeiffer has been with Mr. Obama's team since the 2008 presidential campaign, and he's become one of the president's closest, most trusted advisers. Mr. Obama praised Pfeiffer in a statement announcing his departure.

"Dan has been beside me on every step of this incredible journey, starting with those earliest days of the campaign in 2007, " the president said. "And through it all, he's been smart, steady, tireless and true to the values we started with. Like everyone else in the White House, I've benefited from his political savvy and his advocacy for working people. He's a good man and a good friend, and I'm going to miss having him just down the hall from me."

Pfeiffer first informed the president of his plans to step down the day after Mr. Obama's State of the Union address, when the two men were on Air Force One en route to Boise, Idaho for a speech, according to a White House official. It was something Pfeiffer had been thinking about for a long time, the official added, but given the "position of strength" the White House is now in, he felt it was the appropriate time to make the leap.

During his time at the White House, Pfeiffer was credited with expanding the White House's use of new media and social media to amplify the administration's message. He pushed for the White House to begin breaking news on its blog, the White House official noted, and as recently as last month, he suggested posting the full text of the president' State of the Union on Medium, an online blogging platform, before Mr. Obama delivered the speech.

Pfeiffer and Palmieri join several other high profile White House aides who are headed for the exits. White House counselor John Podesta is scheduled to leave later this month, and he's reportedly in line for a leadership role in Clinton's campaign, if she decides to run. And White House Ebola "czar" Ron Klain will step down from his post on February 15.