President Biden will unleash a full-scale assault on his predecessor’s legacy on Wednesday, acting hours after taking the oath of office to sweep aside former President Donald J. Trump’s pandemic response, reverse his environmental agenda, tear down his anti-immigration policies, bolster the sluggish economic recovery and restore federal efforts aimed at promoting diversity.

Moving with an urgency not seen from any other modern president, Mr. Biden will sign 17 executive orders, memorandums and proclamations from the Oval Office on Wednesday afternoon, according to the president’s top policy advisers.

Individually, the actions are targeted at what the incoming president views as specific, egregious abuses by Mr. Trump during four tumultuous years. Collectively, his advisers said Mr. Biden’s assertive use of executive authority was intended to be a hefty and visible down payment on one of his primary goals as president: to “reverse the gravest damages” done to the country by Mr. Trump, as they said Tuesday.

“We don’t have a second to waste when it comes to tackling the crises we face as a nation,” Mr. Biden said Tuesday night on Twitter after arriving in Washington on the eve of his inauguration. “That’s why after being sworn in tomorrow, I’ll get right to work.”

Mr. Biden’s actions largely fall into four broad categories that his aides described as the “converging crises” he inherits on Wednesday: the pandemic, economic struggles, immigration and diversity issues, and the environment and climate change.

— Michael D. Shear The New York Times