The gun-toting protesters holed-up in a federal wildlife refuge in Oregon said Monday they're not budging until the government addresses their demands.
The tough talk came as the FBI said it was hoping to bring a "peaceful" end to a standoff at the remote Malheur National Wildlife Refuge.
"We feel we have exhausted all prudent measures and have been ignored," said Ammon Bundy, co-leader of the self-styled Citizens for Constitutional Freedom.
They want the U.S. government to "remove its unlawful presence in this county," Bundy said.
Bundy's group seized the government property after splintering off from a larger protest about ranchers' rights in the small town of Burns.
No government employees were at the site at the time because of the holidays. It was not clear how many people had occupied the building, but those inside have asked for others to join them during several videos posted online.
The ringleaders are Ammon and Ryan Bundy — sons of Cliven Bundy, the Nevada rancher known for another standoff with the federal government in 2014.
The FBI said in a statement Sunday that it was working with local and state police "to bring a peaceful resolution to the situation."
The agency said it would not be providing details of its response because of "safety considerations for both those inside the refuge as well as the law enforcement officers involved."
Several pickup trucks continued to block the entrance to the refuge on Monday, with armed men wearing camouflage and winter gear stationed outside.
Although there was no visible sign of police, authorities have warned people to stay away and the county has canceled school until next week as a precaution.
"These men came to Harney County claiming to be part of militia groups supporting local ranchers, when in reality these men had alternative motives to attempt to over throw the county and federal government in hopes to spark a movement across the United States," the Harney County Sheriff's Office said in a statement Sunday. "We ask that people stay away from the refuge for their safety."
The initial protest in Burns was in support of a father and son, Dwight Hammond, 73, and his son Steven, 46, who were about to by jailed for setting fires that spread to government lands after their initial sentences were extended by about four years each.
The Bundy brothers and their followers unveiled a redress of grievances addressed to several local officials and alleged the federal government targeted the Hammonds because they refused to sell their land "to a federal agency."
Bundy insisted he and others had reached out to local officials about the case before taking over the refuge, but never got a response. He said the purpose of the gathering is "to go to work … to unwind the unconstitutional land transactions that have taken place here."
"We have very specific plans that are going to take place," said Bundy, who gave no specifics.
While Bundy claimed to be acting on behalf of the Hammonds, the soon-to-be-jailed ranchers distanced themselves from the protesters and their lawyer told police that "neither Ammon Bundy nor anyone within his group/organization speak for the Hammond family."
The Hammonds' lawyers said in a statement later that the father and son planned to turn themselves in on Monday and serve the "entire sentences imposed in this case by the judge who heard the evidence at trial and who concluded that imposition of a five-year sentence under these circumstances would 'shock the conscience.'"
The lawyer also said the Hammonds plan to appeal to President Obama for executive clemency.
Earlier, Ammon Bundy told NBC's TODAY on Monday that the occupiers have no intention of committing violence unless the government intervenes.
"The only violence that, if it comes our way, will be because government is wanting their building back,'' he said. "We're putting nobody in harm's way. We are not threatening anybody. We're 30 miles out of the closest town."
The Bundys claim they were asked to intervene by an unidentified "county representative" who alleged that "he and other county representatives are being intimidated by the FBI." He did not provide further details of this allegation.
—NBC News' Shamar Walters and Elisha Fieldstadt contributed to this article.
This story originally appeared on NBCNews.com