In this April 2022 photo, Vice President Kamala Harris and former President Barack Obama attend an event to mark the 2010 passage of the Affordable Care Act in the East Room of the White House in Washington, DC.
Washington CNN  — 

Former President Barack Obama is expected to endorse Vice President Kamala Harris soon and his team has been in touch with the campaign, a source told CNN.

Obama and Harris, the presumptive Democratic nominee, have been in touch regularly,?and he is serving as a sounding board for her as he has over the 20 years they’ve known each other, the source said.

Obama, who didn’t immediately endorse Harris following President Joe Biden’s announcement on Sunday that he was not seeking reelection, believed it?was important for the Democratic Party to have a legitimate process through which delegates select their new nominee, and?he thinks Harris is off to an impressive start, the source said.

News of Obama’s expected endorsement was first reported by NBC News.

Regarding Obama’s statement on Sunday, an adviser told CNN that the former president?was taking the same approach as he did in the 2020 Democratic primary, watching closely with the intent of being able to unify the party when a nominee is chosen – whether it was?Harris?or someone else.

Obama’s statement was intended to keep the focus on Biden on the day he announced he was no longer seeking a second term, the adviser said.

The former president was supportive of Biden’s reelection campaign as he?attended multiple fundraisers?that raised millions of dollars, along with participating in moderated conversations with Biden and sending messages encouraging supporters to chip in as part of fundraising efforts.

Democrats have been moving quickly in the process to nominate Harris as the party?adopted the rules?on Wednesday that they will use to?choose their presidential nominee, with voting to officially nominate Harris likely to begin on August 1.

The rules call for ceremonial votes for president and vice president, as well as a vote on the party platform, during the Democratic convention, which is scheduled to take place in Chicago from August 19-22. While the ceremonial presidential vote?will be conducted as a roll call, the vote for vice president is likely to be a voice vote. Harris has not yet selected a running mate.

This story has been updated with additional details.

CNN’s Shania Shelton contributed to this report.