Say no, Joe: Gene Sperling to Biden

House moves from 'fiscal cliff to Boehner cliff': Gene Sperling

Clinton loyalist Gene Sperling said Thursday that Vice President Joe Biden shouldn't jump into the Democratic presidential race.

As director of the National Economic Council from 2011 to 2014, Sperling worked closely with Biden while advising President Barack Obama on the economy.

Sperling told CNBC's "Squawk Box" that from what he gathered before leaving the administration, he believed Biden would not run if Hillary Clinton did.

"[Since then] he's been through quite a lot personally," Sperling said, referring to the death of son Beau Biden from brain cancer in May at age 46. "It's a personal decision for him at the end of the day. I'll respect any decision he makes."

Biden, a former senator from Delaware, unsuccessfully pursued the presidency in 1988 and 2008. If he were to win the White House, Biden would be the oldest person ever elected — turning 74 just 12 days after Election Day 2016.

"I've been with Bill and Hillary Clinton 23 years, and Joe Biden understands that's where my ultimate loyalty is," said Sperling, who also served as National Economic Council director under President Bill Clinton from 1993 to 1996.

Pointing to Hillary Clinton's strong debate performance this week, Sperling said: "She's one of the most qualified people who's ever run for president, in terms of eight years in the White House [as first lady], as a senator from New York, [and] being secretary of state."

"I would like to see people rally around her," he said.