WASHINGTON — US President Joe Biden's administration on Tuesday (June 15) unveiled a plan to address the threat of violence posed by white supremacists and militias, five months after members of those groups joined in a deadly attack on the US Capitol.

The White House released a 30-page plan for increased information sharing between federal and local officials and social media companies, additional resources to identify and prosecute threats and new deterrents to prevent Americans from joining dangerous groups.

The administration conducted a sweeping assessment earlier this year of domestic terrorism that labelled white supremacists and militia groups as top national security threats.

The issue took on new urgency after a Jan 6 assault on the Capitol by supporters of then-President Donald Trump who were trying to overturn Mr Biden's election victory.

The new strategy stopped short of calling for new laws to fight domestic threats, and officials on Tuesday did not offer many details on specific new resources.

"We concluded that we didn't have the evidentiary basis, yet, to decide whether we wanted to proceed in that direction or whether we have sufficient authority as it currently exists at the federal level," said a senior administration official, who spoke on condition of anonymity in advance of the announcement.

In a speech on Tuesday, US Attorney General Merrick Garland said in the "coming days and months" he would convene an interagency task force dedicated to combating domestic terrorism. Mr Garland said he has already "begun to reinvigorate" that task force.

Mr Garland said the Jan 6 attack by Trump supporters had shown white supremacists and militia groups to be the country's greatest domestic security threat.

"In the FBI's view, the top domestic violent extremist threat comes from racially or ethnically motivated violent extremists, specifically those who advocated for the superiority of the white race," Mr Garland said.

In his budget proposal released last month, Mr Biden, who succeeded Trump on Jan 20, sought US$100 million (S$130 million) in additional funding to train and hire analysts and prosecutors to disrupt and deter terrorist activity.

"The threat is elevated," the administration official said. "Tackling it means ensuring that we do have the resources and personnel to address that elevated threat."

The administration is also toughening the federal government's screening methods to better identify employees who may pose insider threats. They are looking to share those techniques with private companies.

That effort includes an ongoing review by the Department of Defense over how and when to remove military members who are found to be engaged in known domestic terrorist groups.

The Defense Department review is looking at, among other things, how to define extremists, the senior administration official said.

"They are doing this in a way they feel ratchets up the protection but also respects expression and association protections," the official said. REUTERS