President Trump departed the White House for the final time as president -- leaving embattled, twice-impeached and with his lowest approval rating in his four years in office.

Trump, in a black suit with a white dress shirt and trademark red tie, alongside outgoing first lady Melania Trump, in a black dress and coat, walked out on a red carpet before Trump briefly spoke to reporters and, for one last time as president, boarded Marine One, to depart the White House.

Trump told reporters the presidency was a "great honor" and an "honor of a lifetime" and that he just wanted to walk over and say "goodbye," adding "hopefully it's not a long term goodbye."

Trump's unconventional, norm-busting approach to the country's institutions -- that will likely outlast the one-term leader and leave a transformative and divisive legacy in Washington -- continue on Biden's Inauguration Day.

He is not greeting the incoming president on the North Portico and joining him to the Capitol, as is tradition, but leaving town early for his Mar-a-Lago Resort in West Palm Beach, Florida, while he still bears the title as president and the aeronautical resources the office provides.

Marine One took a final lap over Washington -- including the Capitol, where Biden’s inauguration preparations are underway.

As Trump continues to refuse to accept the election results, he has also refused to make contact with the incoming president, despite the Biden's staying across the street Monday night in Blair House -- far from the warm welcomes given by previous presidents to their successors, no matter the party lines.

Vice President Mike Pence will not appear at Trump's departure at the White House, nor his "military-style send-off" at Joint Base Andrews. The outgoing vice president is scheduled to attend Biden's inauguration.

Though hours remain in his president, Trump hasn't heard the last of Washington either as he still faces a second impeachment trial in the Senate.

Despite Biden and his family staying just across the street overnight in Blair House -- outgoing President Trump did not invite them to the White House and still has not made contact with the president-elect with just hours to go until one loses the power of the presidency and the other gains it.

Incoming White House communications director Kate Bedingfield was asked directly by ABC News Chief Anchor George Stephanopoulos on "Good Morning America" whether Biden has had "any contact at all, direct contact, with President Trump."

"He has not, no," Bedingfield said.

Trump is skipping Biden's inauguration this morning and the traditional welcome on the White House North Portico to star in his own cold and windy sendoff at Joint Base Andrews while he still bears the title of president  -- making him the first president to skip his successor's swearing since an impeached Andrew Johnson in 1869 snubbed Ulysses Grant.

Biden is waking up as president-elect at Blair House -- across Pennsylvania Avenue from the White House, where in a matter of hours he will enter as the 46th president of the United States.

Assuming the office on his third try for the White House, Biden is assuming a busy schedule for his first day alongside soon-to-be Vice President Kamala Harris -- who is making history as the first woman, first Black woman and first South Asian American to serve as the country’s second in command.

Biden and wife Jill Biden and Harris and husband Doug Emhoff -- the nation’s first second gentlemen -- will begin the morning with Mass at the Cathedral of St. Matthew the Apostle. In a show of unity, Biden extended invitations and is expected to be joined by bipartisan congressional leaders including House Speaker Nancy Pelosi, outgoing Senate Majority Leader Mitch McConnell, Senate Minority Leader Chuck Schumer and House Minority Leader Kevin McCarthy.

The inaugural ceremonies, limited in attendance due to the coronavirus pandemic, begin at 11:30 a.m. at a fortified U.S. Capitol -- two weeks to the date pro-Trump supporters stormed the West Front steps. Harris will be sworn in by Supreme Court Justice Sonia Sotomayor ahead of Biden who will be sworn in by Chief Justice John Roberts at noon, as 25,000 National Guard members patrol the Washington area.

After taking their oaths of office, Biden and Harris will head to Arlington National Cemetery and lay a wreath at the Tomb of the Unknown Soldier with former President Barack Obama and Michelle Obama, President George W. Bush and Laura Bush, and President Bill Clinton and Secretary Hillary Clinton.

Sens.-elect Jon Ossoff and Raphael Warnock of Georgia and Alex Padilla of California will also be sworn into office by the new vice president at an afternoon ceremony at the Capitol -- triggering Democrats taking the majority in the Senate as Harris will cast tie-breaking votes as President of the Senate.

In the evening, Biden will sign executive orders in the Oval Office and swear in Day One appointees in a virtual ceremony. Biden and Harris are then scheduled to deliver remarks before 9 p.m. during the “Celebrating America” inaugural program and close off the night with a wave to the nation from the Blue Room Balcony.

Meanwhile, with their titles until noon, President Trump and first lady Melania Trump are scheduled to depart the White House around 8 a.m. for Palm Beach, Florida, on Air Force One with a “military-style send-off” for Trump as Joint Base Andrews, per his request. Though Trump’s presidency will soon be over, his presence will loom in Washington as he still faces a second impeachment trial in the Senate.

Biden will sign 15 executive actions on this first day as president and ask government agencies to take actions in two areas: extending eviction and foreclosure moratoriums and extending the student loan pause -- in a show of force by Biden as he occupies the Oval Office.

The orders take aim at undoing much of President Trump’s signature and controversial actions during his four years as president, including reversing the travel ban on several predominately Muslim countries, stopping construction of the Mexico border wall, rejoining the Paris Climate Agreement and preserving the Deferred Action for Childhood Arrivals (DACA) program.

Incoming White House press secretary Jen Psaki stressed that while Biden’s actions would directly address some actions taken under Trump, the focus of Biden's Inauguration Day work will be looking ahead.

One of Biden’s orders will direct his Secretary of Homeland Security to take all legal actions to preserve and fortify DACA including sending Congress an 8-year pathway to citizenship for immigrants with no legal status and expanding admissions for refugees into the U.S.

Biden will also rescind the Trump Administration’s 1776 Commission and revoke Trump’s executive order that limited federal agencies from implementing diversity and inclusion training.

His order will also task the Office of Management and Budget with investing in underserved communities and communities of color.

And following last summer’s landmark Supreme Court case that protects LGBTQ+ workers from discrimination, another executive order plans to build off of that to ensure the federal government interprets Title VII and the Civil Rights Act of 1964 by this decision.

The coronavirus pandemic is also a Day One issue and Biden will sign an order implementing his face mask requirement in federal buildings and on federal land, as part of launching his “100 Days Mask Challenge,” which asks Americans to mask up for that time period.

Biden also plans to rejoin the Paris Agreement on Climate Change on his first day in office and encourage federal agencies to review and appropriately address federal actions taken under the Trump administration, including revoking the Keystone pipeline permit.

-ABC News' Justin Gomez and Molly Nagle