Mr Trump has complained that the Democrats’ message was too dark and pessimistic when they held their own scaled-back convention last week.
But excerpts of the president’s prepared remarks suggest he will have plenty of negative things to say, excoriating Mr Biden who ran a centrist campaign for the Democratic nomination.
“At no time before have voters faced a clearer choice between two parties, two visions, two philosophies or two agendas,” Mr Trump is expected to say.
“We have spent the last four years reversing the damage Joe Biden inflicted over the last 47 years.”
Aides said Mr Trump will also make clear that he plans to unite a country that has increasingly shown fractures in the midst of the coronavirus pandemic and nationwide protests over police brutality and racial injustice.
“The Republican Party goes forward united, determined and ready to welcome millions of Democrats, independents and anyone who believes in the greatness of America and the righteous heart of the American people,” the president will say.
He will take the stage on the South Lawn — only the second president to deliver his convention acceptance speech from the White House — convinced that he is on the verge of righting the ship of his battered campaign. Most polls show him trailing Mr Biden in both battleground states and national polling.
The president’s chief advisers say that Mr Trump has been bolstered by the convention and by crisper messaging on the ongoing pandemic.
“Look, the American people like the president’s platform,” said Jared Kushner, White House senior adviser during an event hosted by Politico.
“They like his policies. They want, you know, a president who’s going to be bringing jobs back to America from overseas. They want law and order. They want somebody who can keep their community safe.”
Mr Trump’s speech comes one day after Vice President Mike Pence forcefully defended law enforcement but made no mention of the Black Americans killed by police this year as he addressed convention proceedings that unfolded amid new protests against racial injustice following the latest shooting.
Mr Pence argued that Democratic leaders are allowing lawlessness to prevail from coast to coast. He and others described cities wracked by violence, though protests in most locations have been largely peaceful.
“The American people know we don’t have to choose between supporting law enforcement and standing with African American neighbours to improve the quality of life in our cities and towns,” he said. He attacked Mr Biden for saying there is an “implicit bias” against people of colour and “systemic racism” in the US.
“The hard truth is … you won’t be safe in Joe Biden’s America,” Mr Pence said. “Let me be clear: The violence must stop — whether in Minneapolis, Portland or Kenosha.”
