President Joe Biden on Thursday said "order must prevail", and warned that violent protest is not protected under the US Constitution's free speech and free assembly laws, as tension flared around pro-Palestinian camps across the country's universities.
Mr Biden is facing increasing pressure from Republicans to quell the unrest that has gripped US campuses for weeks.
“Dissent is essential for democracy,” he said the White House. “But dissent must never lead to disorder.”
Hours earlier, police in Los Angeles broke up a pro-Palestinian protest camp at the University of California, one day after the site was attacked by pro-Israel supporters.
“We are not an authoritarian nation where we silence people or squash dissent,” Mr Biden said. “But neither are we a lawless country. We're a civil society and order must prevail.”
He condemned what he said was the prevalence of racism on university campuses.
“There is no place for hate speech or violence of any kind, whether it's anti-Semitism, Islamophobia, or discrimination against Arab Americans or Palestinian Americans, it's simply wrong," Mr Biden said.
"There's no place for racism in America."
Asked if the protests have caused him to reconsider his Gaza policy, he responded: “No.”
The pre-dawn crackdown at UCLA marked the latest flashpoint on US college campuses, where protests over Israel's conduct in the war in Gaza have led to students clashing with each other and police.
Protesters have been calling for universities to disclose their investments and divest from any companies connected to Israel.
Across the country, thousands of people have been arrested and end-of-year lessons, exams and graduation plans have been thrown into disarray.
Former US president and Republican candidate Donald Trump said that the police siege of a building occupied by pro-Palestine protesters at Columbia University in New York was "a beautiful thing to watch".
"I say remove the encampments immediately, vanquish the radicals and take back our campuses for all of the normal students who want a safe place from which to learn," Mr Trump said.
But as universities call for police to clear camps, some are claiming incidents of police brutality.
AP and New York publication The City reported an NYPD police officer fired a gun while clearing demonstrators from Hamilton Hall at Columbia on Tuesday.
Manhattan prosecutors say no one was injured or aimed at as the gun was fired but they are investigating.
At UCLA, police arrested at least 132 people after spending hours warning students they would be detained if they did not disperse. More than 1,000 people had gathered on campus to support the protest.
Protests have spread nationwide including in the US capital, where a pro-Palestine camp has been set up at George Washington University.
Republican politicians have made the trek from Capitol Hill to the campus to denounce the camp and accuse the protesters of anti-Semitism.
On Thursday, Rick Scott, a senator from Florida, visited to say it was “despicable” that pro-Palestinian protesters, who he claimed supported Hamas, were allowed to remain.
Mr Scott called on Washington Mayor Muriel Bowser to order police to clear the camp.
“Look at their signs, they support Hamas,” he told The National.
Determination high at George Washington University protest camp
Dozens of pro-Israel students and supporters gathered in a small park just a block away from the pro-Palestinian students.
Asher Fabes, a second year student at George Washington University, said that while he has never felt personally threatened, the protests have felt anti-Semitic.
“I see the videos at Columbia and all the other places where violence actually breaks out, and it definitely makes me nervous,” Mr Fabes told The National.
“If that can happen at Columbia, then that can happen here.”
Faculty members created a human barrier to protect students camped out in support of Palestine.
“We're very concerned that the students are going to be targeted by counter protesters in ways directed at intimidation, harassment, threats,” said William Youmans, a tenured professor of media and communications at George Washington.
“We all saw what happened to UCLA and we really don't want a replay of that.
“These students are willing to put everything on the line to try to stop a genocide. Tenured faculty really have no excuse for being silent."
Violence erupts on UCLA campus between pro-Palestine protesters and counter-demonstrators
Meanwhile, US intelligence officials appeared to throw cold water on Republican claims that demonstrators were being influenced by adversaries of Washington, such as Hamas or China.
Officials have "yet to see intelligence that Hamas ... is actually influencing the Gaza-related protests occurring in the United States or directing it in any way," the director of national intelligence, Avril Haines, told the Senate armed services committee.
Jeanne Shaheen, a Democratic senator, repeatedly pressed Ms Haines on claims that "Chinese sympathisers are funding some of these protests to exploit the situation in Gaza".
"I am not seeing information that indicates that the Chinese government is directing that," said Ms Haines.
The large police presence at UCLA, including California Highway Patrol and LAPD officers, comes after law enforcement was criticised for being slow to act during violent clashes late on Tuesday, when counter-protesters attacked a camp of pro-Palestinian students.
UCLA said classes would be remote on Thursday and Friday due to the “emergency on campus” and warned students to avoid the protest area.
Demonstrators have gathered at more than 30 US universities since last month, often erecting tents to protest over the rising death toll in the Gaza Strip.
Police tore down a protest camp at the University of Texas on Wednesday, arresting more than a dozen people.
Police dismantle student encampment – in pictures
