WASHINGTON - Chad Wolf, a little-known policy staffer at the US Department of Homeland Security (DHS), will be the agency's new acting secretary, said President Donald Trump, whose hardline immigration policies are spearheaded by the DHS.

There have been a spate of departures at the DHS in recent months that have depleted its leadership ranks. The vacancies left the Republican Trump's administration with no confirmed successor to outgoing acting Secretary Kevin McAleenan, whose resignation was announced last month.

"I put in a very good man who's highly respected, and he's acting right now. We'll see where that goes," Trump said when asked by reporters at the White House on Friday if Wolf would be the next DHS secretary.

White House spokesperson Hogan Gidley said McAleenan would step down after Nov. 11 and Wolf would then assume the position.

Wolf will take control of the department as Trump pushes his immigration crackdown in the runup to the 2020 election.

The secretary plays a crucial and visible role in the implementation of Trump's enforcement agenda. But Wolf, who previously was a top aide to former secretary Kirstjen Nielsen, has kept a low profile during his time in the administration.

Democratic Representative Bennie Thompson, head of the US House Homeland Security Committee, said in a statement that the appointment of "someone without the necessary experience just points to the dysfunction that has plagued DHS since the first days of the Trump administration."

Immigration hawks had pushed for Trump to appoint other candidates, including acting U.S. Citizenship and Immigration Services Director Ken Cuccinelli and acting Customs and Border Protection Commissioner Mark Morgan.

Mark Krikorian, executive director of the Center for Immigration Studies, said the White House should swiftly nominate a more hardline secretary.

"It's not as though he's going to go down and rip up the fence and let people swarm in," Krikorian said. "He isn’t going to have a fire in his belly for carrying out the president's agenda."

Wolf has been criticized by immigration hawks also for past lobbying work for Indian tech companies that backed an expansion of temporary foreign workers.

Sara Blackwell, a Florida-based attorney who supports restrictions on such work visas, called Wolf's appointment "an affront to the American worker.”

Trump could nominate either Cuccinelli or Morgan on a permanent basis, which would please his base. But Senate Republican leader Mitch McConnell spoke in April of his "lack of enthusiasm" for Cuccinelli as a possible candidate. Cuccinelli previously led a political action committee that backed conservative challengers to incumbent Republican senators.