WASHINGTON -- U.S. President-elect Donald Trump pledged to unify what he called a divided nation and to bring change as he arrived in the capital for his January 20 inauguration.
While speaking of unity on the eve on his inauguration, Trump was readying a raft of dramatic measures to roll back policies of his predecessor, Barack Obama, through a series of executive orders targeting Obama's climate-change regulations, immigration liberalization moves, international trade agreements, and restrictions on energy development.
"We're going to unify our country," Trump told a cheering crowd of thousands in front of Washington's Lincoln Memorial after a concert that ended in a burst of fireworks.
"We're going to do things that haven't been done for our country for many, many decades," he said. "It's going to change, I promise you."
As hundreds of thousands of people were expected to celebrate or protest Trump's inauguration in central Washington, Trump gave thanks to the millions who voted for him and made his upset election possible.
"It's a movement like we've never seen anywhere in the world," he said. "You're not forgotten any more... We're going to get it turned around. We're going to bring our jobs back."
Trump's aides said his first hours in office would be marked by dramatic action and that his inaugural address would be shorter than many made by past presidents.
Profile: Donald Trump, America's Next President
"Trump is a man of action, not words, and you'll hear that tomorrow," said incoming White House counselor Kellyanne Conway. His inaugural address on January 20 is set to be an "elegant, beautiful, powerful, and brief speech," she said.
Among Trump's first actions, aides say, will be a freeze on U.S. government hiring, suspension of climate-change regulations, suspension of immigration from countries associated with Islamic extremism, withdrawal from a trans-Pacific trade agreement Obama negotiated, lifting of restrictions on coal mining and oil drilling, and a halt to federal funding for U.S. "sanctuary cities" that refuse to arrest immigrants living in the country illegally.
Some of those decrees were expected to be issued within hours of Trump's swearing-in.
"He is committed to not just Day 1, but Day 2, Day 3 of enacting an agenda of real change," Trump spokesman Sean Spicer said.
While Trump's plans for change were quickly taking form, how he would unify a nation where millions still reject his presidency remained unknown.
One-third of the Democrats in the U.S. House have said they plan to skip his inauguration. Earlier this week, a Washington Post-ABC News survey found Trump’s 40 percent approval rating was the lowest of any incoming president-elect since Jimmy Carter in 1977.
Confirmation hearings for Trump’s cabinet nominees this week have been marked by often testy questions from lawmakers, particularly Democrats, amid concerns about the nominees’ qualifications and potential conflicts of interests.
Earlier this month, U.S. intelligence agencies said they had concluded "with high confidence" that Russian President Vladimir Putin "ordered an influence campaign in 2016 aimed at the U.S. presidential election."
They also charged that Putin and the Russian government "developed a clear preference" for Trump over his rival in the November 8 vote, Hillary Clinton.
Tom Barrack, the chief architect of Trump's inaugural festivities, said Trump would show the world that "we can argue, we can fight, and we can debate," but then the nation unites behind one president.
Obama also had vowed he would unify the country and end the sharp partisan divide in Washington, but admitted after eight years in office that he had failed to reach that goal.
Some Trump fans who came to Washington were optimistic about Trump's prospects.
"We're hoping for good weather and hoping for some unity," Jon-Paul Oldham, a firefighter from the state of Connecticut, told AP. He said everyone should want Trump to succeed.
"Wanting him to fail is like wanting the plane to crash, but you're on the plane," Oldham said.
Tens of thousands of law enforcement officers and kilometers of barriers were in place in Washington, as about 900,000 people were expected to gather in the center of the capital, including the National Mall facing the Capitol, where Trump will be sworn in, and the parade route along Pennsylvania Avenue to the White House.
Meanwhile, opponents were planning to hold anti-Trump protests throughout central Washington. One of the largest such demonstrations is to be organized by the ANSWER Coalition.
"It's Day One, we're saying, of a larger era of resistance, and we believe we're going to send a very powerful message to Trump and the government," said Ben Becker, an organizer with the group. "The Trump agenda is very comprehensive. It includes attacks on Muslims, immigrants, on women's rights, on workers' rights."
On the streets of New York, Hollywood actor Robert de Niro and other celebrities joined several thousand protesters to demonstrate against the president-elect on the eve of his inauguration.
"Whatever happens, we Americans, we New Yorkers, we patriots, will stand united for our rights and for the rights of our fellow citizens," de Niro said.
Meanwhile, Russian Prime Minister Dmitry Medvedev expressed hope that Trump's inauguration will be the start of a period of better ties with the United States.
While it's not clear what course Trump will take, Medvedev wrote on his Facebook page, "we are ready to do our share of the work in order to improve the relationship."
Trump has said he wants to improve U.S.-Russia relations, which have sunk to lows unseen since the Cold War amid rancor over Moscow's seizure of Ukraine’s Crimean Peninsula in 2014, its backing of separatists in eastern Ukraine, its involvement in the Syrian conflict, and other issues.
With reporting by AP, AFP, and Reuters