U.S. President Barack Obama attends a roundtable meeting at Rutgers University Law & Justice Center in Newark Thomson Reuters US President Barack Obama will not publicly endorse a candidate before the 2016 Democratic primary has concluded, White House Chief of Staff Denis McDonough said on Sunday.

"We'll do exactly what has been done in the past," McDonough said on NBC's "Meet the Press."

When asked specifically by host Chuck Todd if the president would endorse a candidate, McDonough shook his head.

"No, no," he said.

McDonough acknowledged that though the president had privately met several times with Democratic presidential candidate Hillary Clinton, who served as Secretary of State during Obama's first term, he had not met with Sen. Bernie Sanders (I-Vermont) since the senator jumped in the race eight months ago.

McDonough did say that Obama will be "out there" campaigning after the primary to help support the Democratic candidate.

The president's decision to stay above the fray in the primary has plenty of precedent.

In 2008, then-President George W. Bush did not endorse the Republican presidential nominee, Sen. John McCain (R-Arizona) until the senator won several key primaries, making it apparent that he would likely be the nominee.