White nationalist Richard Spencer speaks Oct. 19 at the University of Florida in Gainesville. (Chris O'Meara/AP)

The property manager at the Ronald Reagan Building and International Trade Center has rejected a request by white nationalist Richard Spencer to host a conference in the building, citing security concerns.

The think tank that Spencer heads, the National Policy Institute, had planned to host a conference in the federal building Nov. 19. The two sides had been in communication for months about the event.

Debra Cope, a spokeswoman for CommCore Consulting, the crisis-management firm the building’s property management company hired to handle reaction to the rejection, said the decision was made because of concerns about safety.

“We have never and would never decline a meeting on the basis of the content of the speech,” she said. “But we concluded it would be difficult, if not impossible, to secure the safety of everyone, including participants in the meeting.”

White nationalist Richard Spencer clashes with Virginia police in Lee Park after the “Unite the Right” rally was declared an unlawful gathering Aug. 12 in Charlottesville. (Chip Somodevilla/Getty Images)

Spencer’s public appearances have been a lightning rod for controversy in recent months, both for the content of his speeches and questions over free speech. His events typically attract large numbers of protesters, raising safety concerns.

The University of Florida reluctantly agreed last month to allow Spencer to speak on campus after it initially rejected his request. Spencer and his lawyer challenged that initial decision, citing First Amendment concerns. The university ended up paying hundreds of thousands of dollars to increase security for the event.

Spencer’s group has held multiple events at the Reagan Building. He said Thursday that he was “shocked” by the decision.

“One of the reasons why we use this building is because it is a federal facility,” Spencer said. “This is not a private facility canceling on us — this is a federal facility. This seems to be a First Amendment issue.”

The building, which is owned by the General Services Administration and used by both the government and private sector, is the site of hundreds of events each year. It is operated by Trade Center Management Associates (TCMA), a private-sector building management and hospitality service provider.

Spencer said the event was intended to be a policy conference, which would feature Daniel Friberg, the European editor of AltRight.com, and Kevin MacDonald, who is described by the Southern Poverty Law Center as “the neo-Nazi movement’s favorite academic.” Spencer said he had expected about 125 people to attend.

“This is more of a coat-and-tie policy conference,” Spencer said. “This was not a rally at all. There would have been two meals. It was a very different event than some of the more raucous ones that I’ve done.”

Spencer’s organization would have paid to use space in the government building.

TCMA said in a statement that the violence that unfolded after Charlottesville in August, as well as disruptions that occurred at other National Policy Institute events in the building, led them to reject hosting the conference.

“We concluded that extraordinary and costly measures would need to be taken to protect against the significant risk of violence and injuries posed to our clients, event attendees, tenants, employees and the general public, as well as damage to the property,” the company said.

Spencer was one of the leaders of a white-nationalist rally in Charlottesville in August. The march at the University of Virginia — with participants chanting “Jews will not replace us!” — touched off violence between demonstrators and counterprotesters that turned deadly the next day when a man drove into a crowd, killing one woman and injuring others. Two police officers who were monitoring the protests died when their helicopter crashed.