Vice President JD Vance, who guest-hosted the slain conservative activist's livestream show, amplified right-wing calls for a broadside against leftist groups after Kirk was assassinated last week as he addressed college students.
White House Deputy Chief of Staff Stephen Miller, Vance's guest on the program, said Kirk's final message to him called for a co-ordinated effort against unnamed left-wing groups accused of promoting violence, pledging the federal government would use "every available resource" to dismantle them.
"With God as my witness, we are going to use every resource we have at the Department of Justice, Homeland Security and throughout this government to identify, disrupt, dismantle and destroy these networks and make America safe again for the American people," he said.
"It will happen, and we will do it in Charlie's name."
Later, Miller told reporters at the White House that President Donald Trump's administration is looking at holding criminally accountable a network of "nonprofit entities" that organise attacks on law enforcement, use doxxing and supply materials used in riots. He did not provide evidence of such wrongdoing.
The remarks by top Trump administration officials on Monday offered the clearest indication yet of what steps the White House is weighing in response to Kirk's death. Critics have for days expressed worry that Trump would use Kirk's assassination as a pretext to crack down on political opponents.
Investigators are yet to piece together why the suspected gunman, Tyler Robinson, allegedly shot Kirk on Wednesday.
Investigators found messages engraved into four bullet casings, which included references to memes and video game in-jokes, though experts warned that the messages offered no clear indications about a political motivation.
A wave of violence across the political spectrum has afflicted the United States in recent years, targeting both Democrats and Republicans.
Trump, who has a history of using severe rhetoric against political opponents, blamed the "radical left" almost immediately after Kirk was shot and before a suspect was identified.
On Friday, police arrested 22-year-old Robinson, of Utah, and charged him with Kirk's murder. State records show Robinson was a registered voter but had no political party affiliation.
