Biden, in a speech at the White House after Trump's victory, urged Americans to “accept the decision that the country has made.”

WASHINGTON — President Joe Biden addressed the nation Thursday after Donald Trump's decisive victory, urging Americans to “accept the country's decision” while encouraging his supporters to “rise back up.”

“We accept the country’s decision,” he said in brief remarks in the White House Rose Garden. “I have often said that you cannot only love your country when you win. You can’t love your neighbor only when you agree.”

Biden's speech comes four years after he was projected to win the 2020 election against Trump, who has insisted for years that those results were rigged and sought to overturn them.

“I will fulfill my duty as president: I will fulfill my oath and honor the Constitution. On January 20th, we will have a peaceful transfer of power here in America,” Biden said Thursday.

Biden acknowledged that his administration's achievements have not yet been felt by the American people and suggested that it will take years for the impact to be felt. He said the legislation he signed is just now “really coming into effect,” adding that $1 trillion in infrastructure work will be done and transform the lives of people in rural communities and other struggling places.

“It takes time to get it done,” he said, adding that he would leave behind “the strongest economy in the world.”

He also urged Americans disappointed by Harris' loss not to give up.

“Setbacks are inevitable, but giving up is unforgivable. We all get knocked down, but the measure of our character, as my father would say, is the speed at which we get back on our feet. Remember, defeat does not mean we are defeated,” Biden said. “We lost this fight. The America of your dreams is calling you to rise again.”

Trump's victory was a blow to Democrats, who had hoped to elect Vice President Kamala Harris as the first female president. Instead, Trump expanded his base and captured several battleground states that Biden flipped in 2020: Pennsylvania, Georgia, Michigan and Wisconsin.

Harris acknowledged Trump by telephone Wednesday morning and addressed her supporters in remarks later in the day at Howard University, her alma mater.

“Today I spoke with President-elect Trump and congratulated him on his victory. I also told him that we will help him and his team in their transition and engage in a peaceful transfer of power,” she said.

She added: “A fundamental principle of American democracy is that when we lose an election, we accept the results.”

Biden also called Trump and congratulated him on his victory.

“President Biden expressed his commitment to a smooth transition and emphasized the importance of working to bring the country together,” the White House said. “He also invited President-elect Trump to meet with him at the White House. The staff will arrange a specific date in the near future.”