Homeland Security Secretary Alejandro Mayorkas on Sunday said the threats facing the U.S. in the 21 years since the Sept. 11 attacks have shifted from worries about foreign terrorists to growing concerns about domestic extremism.

“The threat landscape has evolved considerably over the last 20 years,” Mayorkas said during an appearance on MSNBC’s “The Sunday Show with Jonathan Capehart.” 

“Back when 9/11 occurred, in those years we were very focused on the foreign terrorist, the individual who sought to do a severe harm to enter the United States and and do us harm,” Mayorkas continued, speaking at the site of the World Trade Center.

But now, Mayorkas said officials are becoming “more and more” concerned about U.S. residents radicalized by foreign terrorist ideologies.

“We are seeing an emerging threat, of course, over the last several years of the domestic violent extremist,” Mayorkas said. “The individual here in the United States radicalized to violence by a foreign terrorist ideology, but also an ideology of hate, anti-government sentiment, false narratives propagated on online platforms, even personal grievances.”

Mayorkas has previously called domestic extremism the country’s greatest terror-related threat, comments that came less than three months after the Jan. 6, 2021, Capitol attack.

Mayorkas is one of many Democrats who have sounded alarm bells about domestic extremist threats. 

Vice President Harris in an interview on NBC’s “Meet the Press,” which also aired on Sunday, called domestic terrorism “very dangerous,” saying it makes the country “weaker.” 

Asked if domestic threats are equal or greater than those the U.S. faced after 9/11 from foreign terrorists, Harris said “we don’t compare the two in the oath” to protect the country.

Sen. Mark Warner (D-Va.), the Senate Intelligence Committee chairman, said on Sunday that he worries about domestic threats while the threat of terror in his view had “diminished.”

“The stunning thing to me is here we are 20 years later, and the attack on the symbol of our democracy was not coming from terrorists, but it came from literally insurgents attacking the Capitol on Jan. 6,” he said on CBS’s “Face the Nation.”

The House in May passed a bill nearly along party lines that would create domestic terrorism offices throughout the federal government. Rep. Adam Kinzinger (Ill.) was the sole House Republican to vote in favor of the legislation, while others in his conference argued the bill would unfairly target Americans.