Story highlights Barack Obama is poised to deliver a Hillary Clinton endorsement as soon as this week, two Democrats tell CNN

Democrats are still holding out hope for a large-scale unity event

(CNN) President Barack Obama's long wait to hit the campaign trail is about to come to an end.

With Hillary Clinton set on Tuesday to secure enough delegates and become the presumptive Democratic nominee, the White House is signaling that Obama's full endorsement could come as early as this week.

White House officials and Democratic aides are still determining how and when Obama, along with Vice President Joe Biden, will throw their formal endorsements behind Clinton and her campaign. Eager to exploit his recent spike in popularity, Obama is looking to become the most active lame duck campaigner in recent presidential history.

Even as Sen. Bernie Sanders pledges to keep fighting until the Democratic convention, Clinton and her allies are planning a major push to unify the party behind her candidacy, including a high-profile endorsement Obama is poised to deliver as soon as this week, two Democrats familiar with the effort tell CNN.

While he has formally remained neutral in the race between Clinton and the Vermont independent senator, Obama has inched closer and closer to Clinton's side in recent weeks and will take the final step after the last round of states vote on Tuesday. The Clinton campaign in Brooklyn is working with the White House to coordinate the effort.

Read More