ORLANDO (AP) — Less than six weeks after leaving office, former President Donald Trump will deliver the closing speech at a conservative conference Sunday as he reasserts himself on the national stage and makes clear he intends to remain a dominant force within the Republican Party.

How to watch: Donald Trump was scheduled to speak at 3:30 p.m. Eastern, but the start time was delayed. Fox News reported it could be as late as 4:55 p.m. Eastern. CPAC is being shown on C-SPAN. There is also a CPAC livestream at live.conservative.org

Aides say Trump will use the speech at the Conservative Political Action Conference to blast his successor, President Joe Biden, and try to cement his status as the party’s undisputed leader going forward despite his loss in November.

“I stand before you today to declare that the incredible journey we began together four years ago is far from over,” Trump will say, according to excepts of his speech released early. “We are gathered this afternoon to talk about the future — the future of our movement, the future of our party, and the future of our beloved country.”

The event so far at a Hyatt hotel in Orlando, Florida, has been a tribute to Trump and Trumpism, complete with a golden statue in his likeness. Speakers, including many potential GOP 2024 hopefuls, have argued the party must embrace the former president and his followers, even after the deadly insurrection at the Capitol on Jan. 6. They stand in opposition to others who argue the party must move in a new, less divisive direction after Republicans lost not only the White House but both chambers of Congress in the last elections.

“The least popular (leaders) in our party are the ones who want to erase Donald Trump and Donald Trump’s supporters from our party,” said Rep. Jim Banks of Indiana, the chair of the conservative Republican Study Committee, during a Saturday panel discussion. “And let me tell you, if that happens, we won't win back the majority in 2022. We definitely won’t win back the White House in 2024 if we erase Donald Trump."

On Biden, Trump is expected to deliver a sharp rebuke of what he will frame as the new administration's first month of failures, including Biden's approach to immigration and his decision to halt construction of Trump's southern border wall, his foreign policy posture and his handling of the economy as the country continues to grapple with the coronavirus pandemic.

It is highly unusual for past American presidents to publicly criticize their successors so soon after leaving office. Ex-presidents typically step out of the spotlight for at least a while; Barack Obama was famously seen kitesurfing on vacation after he departed, while George W. Bush said he believed Obama “deserves my silence" and took up painting.

Not Trump.

White House press secretary Jen Psaki brushed off the expected criticism. “We’ll see what he says, but our focus is certainly not on what President Trump is saying at CPAC," she told reporters.

Aside from criticizing Biden, Trump is expected to use the speech to discuss the future of the Republican Party and his “America First” movement, arguing they must stick with him to keep the new voters he brought into the party energized. And he will argue the only divide in the party is between Washington elites and the conservative grassroots, even as he seeks to punish those he has deemed insufficiently loyal, including Senate Minority Leader Mitch McConnell and the No. 3 House Republican, Rep. Liz Cheney.

Indeed, on Friday, Trump began his vengeance campaign, endorsing Max Miller, a former aide who is seeking to oust Ohio Rep. Anthony Gonzalez, who voted in favor of Trump's impeachment.

While he no longer has his social media megaphone after being barred from Twitter and Facebook, Trump has already been inching back into public life. He called into conservative news outlets after Rush Limbaugh's death and to wish Tiger Woods well after the pro golfer was injured in a car crash. He has also issued statements, including one blasting McConnell after the Senate Republican leader excoriated Trump for inciting the Capitol riot. McConnell has since said he would “absolutely” support Trump if he were the GOP nominee in 2024.

At his Mar-a-Lago club in Palm Beach, Florida, Trump has been quietly meeting with aides and senior party leaders as he builds his post-presidential political operation. While he has already endorsed several pro-Trump candidates, aides have been working this past week to develop benchmarks for those seeking his endorsement to make sure the candidates are serious and have set up full-fledged political and fundraising organizations before he gets involved.

They are also planning a new super PAC that could raise unlimited amounts of money, though one aide cautioned they were still deciding whether to create a new entity or repurpose an existing America First super PAC.

Trump is not expected to announce Sunday that he will run again in 2024, but allies made clear he would continue to float the prospect.

“You are going to see a speech on Sunday that talks about not only the beginning but what the future may look like," Trump’s former chief of staff Mark Meadows told Fox News Channel's Sean Hannity earlier this week. “What we will see on Sunday is we will see the start of planning for the next administration. And I can tell you, the people that are in the top of that list, all of 'em have Trump as their last name."

“I imagine it will not be what we call a ‘low-energy’ speech,” said Trump’s eldest son, Donald Trump Jr., during his own speech on Friday to CPAC — or “T-PAC” as he called it. “I assure you that it will solidify Donald Trump and all of your feelings about the MAGA movement as the future of the Republican Party.”

Staff writer Brian O’Shea contributed to this article