WASHINGTON — The Biden administration will examine if additional F.B.I. agents are needed at the bureau’s field offices to address the threat of domestic violent extremism, a senior administration official said on Friday.

Last month, the White House ordered a review of the threat of domestic violent extremism, led by the Office of the Director of National Intelligence. That assessment will inform a policy review that will consider F.B.I. resources, additional authorities, foreign influence operations and other questions.

The senior administration official said that the assessment and initial policy review would take about 100 days. The official spoke on a conference call with reporters on ground rules of anonymity to broach current policy discussions.

The issue of violent extremist groups in the United States has come to the top of the agenda since a mob of far-right extremist organizations stormed the Capitol on Jan. 6. The assault, which aimed to stop the counting of Electoral College votes and halt the transition of power to the Biden administration, has led to a string of federal charges against the rioters.

Since the attack, there have been a series of questions about the intelligence gathered before Jan. 6, and whether the federal government was taking the threat of violence and extremist groups seriously enough.

There is broad interest across the government in the issue of violent domestic groups. On Thursday, both Democrats and Republicans on the House Homeland Security Committee expressed support for new domestic terrorism laws intended to stop violence similar to the attack on the Capitol. And Senator Mark Warner, Democrat of Virgina, who is the new chairman of the Senate Intelligence Committee, said this week that he had bipartisan support for his panel to investigate the matter.

In a letter last month to President Biden, Senator John Cornyn, Republican of Texas and a member of the intelligence committee, backed the administration’s assessment request and asked that the role of foreign adversaries be examined.

“It is crucial we understand the full extent of the threat facing our nation to ensure the tragic events of Jan. 6, 2021, never happen again,” Mr. Cornyn wrote.

The administration official said the bulk of the intelligence review would fall to the intelligence arms of the F.B.I. and Department of Homeland Security, but it is the role of the director of national intelligence to coordinate assessments that involve multiple departments.

However, an element of the review will look at potential links between domestic groups and foreign networks and organizations, the official added. That part of the review will involve intelligence agencies, including the C.I.A. and National Security Agency, which are restricted in their collection of intelligence on Americans.

White House officials expect that as part of the policy review, the F.B.I. will seek additional resources to deal with domestic violent extremism. The official noted that a Department of Homeland Security examination found that white supremacist terrorism was the most lethal domestic threat from 2018 to 2020.

While some F.B.I. field offices have a squad of agents who deal primarily with the threat of domestic extremist groups, not all of them have a full contingent of resources dedicated to the fight. However, former F.B.I. officials say the domestic terrorism threat can vary from state to state.

But the official said another part of the review would look at whether the bureau’s Joint Terrorism Task Forces were structured to address the threat of American extremist groups and antigovernmental organizations. The review will look at whether the task forces are capable of reporting episodes of domestic violent extremism and track the groups that are involved, the official said.

International terrorist groups, like Al Qaeda, are far more hierarchical. In contrast, the official said, domestic extremist groups are more loosely organized. Membership can shift, and different groups can come together, as they did during the Capitol attack, and then split apart.

Adam Goldman contributed reporting.