WASHINGTON -- Joe Biden became the 46th president of the United States on Wednesday, promising to repair the country's global leadership, as well as its relationship with allies.

The former vice president took the oath of office on the steps of the Capitol in an inauguration ceremony with only a few participants and nearly no spectators.

Biden and his transition team had noted the need to keep this year's ceremony at a minimum, stressing the need for people to keep social distance as a way of preventing the spread of the virus, which has already claimed more than 400,000 American lives.

The need to keep it small and simple became more apparent after a large group of violent protesters breached the Capitol two weeks ago, on Jan. 6, just as Congress was ready to certify Biden as the winner of the presidential election.

Areas near the White House and the Capitol have since been on lockdown, with tens of thousands of National Guard soldiers expected to safeguard the areas until after the inauguration.

Ceremony organizers have said the traditional parade that follows the inauguration of a new president will also be held virtually this year.

Outgoing President Donald Trump skipped Biden's swearing-in ceremony, becoming the first sitting US president to boycott a presidential inauguration since 1869.

The former president left for Florida early in the morning after holding a brief meeting with a handful of his supporters.

Former Presidents Bill Clinton, George W. Bush and Barack Obama attended the inauguration, along with their wives. Former President Jimmy Carter was unable to attend.

Trump continues to reject his defeat, accusing Biden and his Democratic followers of stealing the election.

He, however, now faces an impeachment trial by the Senate, partly for his challenges to the election system that many courts, including the US Supreme Court, have dismissed as groundless.

Trump was impeached for a second time by the House of Representatives earlier this month for allegedly inciting the Jan. 6 insurrection at the Capitol.

While Trump's impeachment trial may reflect the wide political divide that still exists after the Nov. 3 election, Biden called for unity in his first address to the nation as president.

"I ask every American to join me in this cause ... to fight the foes we face -- anger, resentment and hatred, extremism, lawlessness, violence, disease, joblessness and hopelessness. With unity, we can do great things, important things," he said.

Prior to the election, the former vice president had promised to build America back better but has since emphasized the need to build a "better united" US.

While Biden is expected to bring significant changes in nearly every aspect, including how the US deals with its allies, simply by giving up Trump's "America First" policy, his inaugural addressed showed that his early days as president will likely be spent on domestic issues, such as the pandemic, its economic fallout and racial justice.

Still, Biden also underlined the importance of working with US allies.

"We will repair our alliances and engage with the world once again, not to meet yesterday's challenges but today's and tomorrow's challenges," he said.

"We will be a strong and trusted partner for peace, progress and security," added the new US president.

Biden did not address North Korea or the risks posed by its nuclear weapons.

However, his pick for secretary of state, Antony Blinken, on Tuesday said the new administration will review the country's "entire approach and policy" toward North Korea.

"I think we have to review and we intend to review the entire approach and policy toward North Korea because this is a hard problem that has plagued administration after administration, and it's a problem that has not gotten better," Blinken said in his confirmation hearing before the Senate Foreign Relations Committee.

He said the Biden administration will also work with US allies, including South Korea, to deal with risks posed by countries such as North Korea.

"We can revitalize our core alliances -- force multipliers of our influence around the world. Together, we are far better positioned to counter threats posed by Russia, Iran and North Korea and to stand up for democracy and human rights," Blinken said.

North Korea has refrained from any major provocations, also maintaining its self-imposed moratorium on nuclear and long-range missile testing since November 2017.

Its leader, Kim Jong-un, however, has called for continued efforts to further develop the country's nuclear capabilities, along with delivery systems. (Yonhap)