President Donald Trump began issuing what was expected to be a barrage of executive orders Monday, including major steps to crack down on immigration and dismantle diversity initiatives in the federal government, kicking off his presidency with a muscular use of power intended to signal a sharp reversal from existing policies.

The flurry of executive actions is an effort to roll back many of former President Joe Biden’s most significant domestic policies, primarily on climate and immigration, while reimposing a Trump agenda that would launch drilling and mining on natural resources and fundamentally upend the United States’ global role as a sanctuary for refugees and immigrants.

Trump has promised a burst of action, saying in his inaugural speech: “With these actions, we will begin the complete restoration of America and the revolution of common sense.”

It was unclear how many directives Trump intended to sign Monday afternoon, but he has promised close to 100 in the coming days.

Some of the orders will likely be challenged in court and others will be largely symbolic. But taken together, they will amount to a sharp turn in direction after the Biden administration, an effort to begin to make good on his campaign promises, and initial steps toward breaking what he and his aides see as a “deep state” effort to thwart his agenda.

Top advisers briefed reporters on many of them. Here are some of the major elements.

Immigration and the border

Close the border to asylum-seeking migrants.

Declare an end to birthright citizenship, a guarantee granted by the 14th Amendment, for the children of immigrants in the country illegally. The president cannot change the Constitution on his own, so it’s not yet clear how Trump plans to withhold the benefits of citizenship to a group of people born in the United States. The move is all but certain to be challenged in court.

Involve the U.S. military in border security. This would draw immediate legal challenges because of the strict limits in U.S. law for how the armed forces can be deployed inside the country.

Declare migrant crossings along the U.S.-Mexico border to be a national emergency, which would allow Trump to unilaterally unlock federal funding for border wall construction, without approval from Congress, for stricter enforcement efforts.

Designate drug cartels as “global terrorists.”

Federal workforce

End remote-work policies and order many agencies back to the office 4 or 5 days a week.

Gender, diversity, equity and inclusion

Establish biological sex definitions for federal workers and as part of revised Title IX guidance to schools.

Remove protections for transgender people in federal prisons.

Remove protections for transgender migrants in U.S. custody.

Tariffs and trade

Direct federal agencies to begin investigating trade practices, including trade deficits, unfair currency practices, counterfeit goods and a special exemption that allows low-value goods to come into the U.S. tariff-free.

Assess China’s compliance with a trade deal Trump signed in 2020, as well as the United States-Mexico- Canada Agreement, which Trump signed in 2020 to replace the North American Free Trade Agreement.

Order the government to assess the feasibility of creating an “External Revenue Service” to collect tariffs and duties.

Energy and the environment

Declare a national energy emergency, which could allow him to unlock powers to speed permitting for pipelines and power plants.

Order the federal government to roll back regulations that impede domestic energy production.

Signal an intention to loosen the limits on tailpipe pollution and fuel economy standards, which Trump refers to as an “electric vehicle mandate.”

Roll back energy-efficiency regulations for dishwashers, shower heads and gas stoves.

Open the Alaska wilderness to more oil and gas drilling.

Eliminate environmental justice programs across the government, which are aimed at protecting poor communities from excess pollution.