Updated at 6:51 p.m. ET

Chad Wolf, acting secretary for the Department of Homeland Security, is stepping down, according to a senior department official.

Wolf’s departure from the Trump administration, just days before the president’s norm-shattering term is set to come to a close, is the most recent Cabinet resignation since last week. Several other officials in the Trump administration have left since Wednesday, citing the deadly insurrection on Capitol Hill.

Wolf, who built a reputation as the enforcer behind some of Trump’s more extreme immigration crackdowns, said in a letter to department staff: “I am saddened to take this step, as it was my intention to serve the Department until the end of this Administration.”

Wolf did not directly reference the violent mob that overtook Capitol Hill as the cause for his departure.

“Unfortunately, this action is warranted by recent events, including the ongoing and meritless court rulings regarding the validity of my authority as Acting Secretary. These events and concerns increasingly serve to divert attention and resources away from the important work of the Department in this critical time of a transition of power,” he said.

DHS oversees the U.S. Secret Service, which is charged with protecting high-ranking public figures, including the president-elect. Wolf’s departure throws the already embattled agency into turmoil just days before President-elect Joe Biden’s planned inauguration, which faces new security concerns following last week’s attempted insurrection by Trump supporters at the U.S. Capitol.

The department has not had a Senate-confirmed secretary since Kirstjen Nielsen’s ouster in April 2019. Wolf has been serving as the department’s secretary in an acting capacity since November 2019.

Compounding the agency’s problems, DHS has come under legal scrutiny in recent months regarding Wolf’s enforcement of certain immigration measures and whether he acted lawfully to uphold the strict policies.

Wolf had previously been nominated by Trump to lead the department in its full capacity. But the White House withdrew that nomination last week, hours after Wolf condemned the violence on Capitol Hill and called on the president to do the same.

After the violence at the Capitol, Wolf had indicated he planned to remain in his post until Jan. 20 to help with an orderly transition of power amid the heightened security threats facing the country.

Wolf will be replaced by Federal Emergency Management Agency Administrator Peter Gaynor.

Online, immigration advocates cheered Wolf’s departure.

Acting roles draw scrutiny

Wolf’s service in an acting capacity was part of a pattern by the Trump administration. Democrats say Trump bypassed Congress by installing acting officials at all levels instead of Senate-confirmed ones to avoid congressional scrutiny or rejection.

William Perry Pendley led the U.S. Bureau of Land Management for nearly a year before the White House formally nominated him in June to lead that agency. Under pressure from Democrats and some Republicans who called the former oil industry lobbyist too political a choice, Trump withdrew Pendley’s nomination in August.

A month later, as Pendley appeared still to be serving as acting BLM director, a federal judge ordered him to step down in response to a lawsuit from then-Montana Gov. Steve Bullock, a Democrat. Pendley continues to work for the agency, but in a role that he and the administration say is not as a temporary agency head. In September, the Trump administration said it would appeal the court ruling but offered no timeline for doing so.

NPR’s Brian Naylor and Kirk Siegler contributed to this report.

Updated at 4:25 p.m. ET

The Trump administration is designating Cuba as a state sponsor of terrorism in a move that will return the island nation to the pariah list from which it was removed five years ago.

As he announced the designation Monday, Secretary of State Mike Pompeo accused Cuba of “repeatedly providing support for acts of international terrorism in granting safe harbor to terrorists.”

Pompeo also said the Trump administration is intent on “denying the Castro regime the resources it uses to oppress its people at home, and countering its malign interference in Venezuela and the rest of the Western Hemisphere.”

The Cuban foreign minister Bruno Rodríguez tweeted, “We condemn the hypocritical and cynical designation of Cuba as a state sponsor of terrorism announced by the US. The political opportunism of this action is recognized by anyone with an honest regard for the scourge of terrorism and its victims.”

The U.S. removed Cuba from its state sponsors of terrorism list in May 2015. President Barack Obama’s administration had reached an agreement to restore relations with Cuba months earlier, including a plan to boost travel and trade between the two countries.

“The world is upside down,” Cuban diplomat José Ramón Cabañas said late last week as news spread of the pending change. He noted that the Cuban Embassy in Washington, D.C., came under an armed attack in April – an incident in which a Texas man was arrested on assault and weapons charges.

Sen. Patrick Leahy blasted the move, saying, “This blatantly politicized designation makes a mockery of what had been a credible, objective measure of a foreign government’s active support for terrorism.”

“Nothing remotely like that exists here,” the Democrat from Vermont said in a Monday statement, adding that the move will make U.S.-Cuba relations more difficult for the Biden administration to deal with.

Being put on the U.S. terror list exposes countries to a suite of sanctions, including “restrictions on U.S. foreign assistance; a ban on defense exports and sales; certain controls over exports of dual use items; and miscellaneous financial and other restrictions,” the U.S. State Department says.

The State Department currently lists only three countries as state sponsors of terrorism: Syria, Iran and North Korea.

In a much-anticipated move, the U.S. formally took Sudan off the list last month as part of a deal in which the country agreed to normalize relations and open economic ties with Israel.

The Trump administration has steadily reversed many of the steps Obama took to end Cuba’s isolation. In the spring of 2019, it placed new sanctions and penalties on Cuba, hoping to undermine the communist regime. It also killed a deal that would have made it easier for Cuban baseball players to join professional teams in the U.S. and Canada.

Two months later, the United States imposed new travel restrictions to stop U.S. citizens from visiting the island on cruise ships and other travel.

And in May it returned Cuba to a list of countries that the U.S. deems as “not cooperating fully” with its counterterrorism efforts. It cited the country’s refusal of a request from Colombia to extradite leaders of the National Liberation Army and said Cuba has harbored “several U.S. fugitives from justice.”