NEWARK, N.J. —After more than three months in ICE detention, Columbia University student Mahmoud Khalil returned to the New York area where his harrowing ordeal first began.

Immigration authorities had arrested Khalil, 30, in March at the university housing complex where he lived in New York City. He was quickly transported thousands of miles away to a detention center in Louisiana, where he spent the last few months.

Khalil remained defiant as he spoke to reporters and supporters on Saturday afternoon upon his arrival at Newark International Airport.

“Your messages have kept me going. Still the fight is far from over, the genocide is still happening in Gaza, Israel is still waging a full war against Palestine,” said Khalil, who was flanked by his wife Dr. Noor Abdalla and Rep. Alexandria Ocasio-Cortez. “The U.S. government is funding this genocide and Columbia University is investing in this genocide. This is why I was protesting, this is why I will continue protesting with every one of you, not only if they threaten me with detention. Even if they would kill me, I would still speak up for Gaza.”

When asked what his message would be to the Trump administration, Khalil said, “Just the fact that I’m here sends a message.”

“The fact that all of these attempts to suppress pro-Palestine voices have failed now,” he said. “This is the message. My existence is a message.”

Ocasio-Cortez said Khalil’s imprisonment for politically motivated.

“Everybody agrees that persecution based on political speech is wrong and is a violation of all of our First Amendment rights, not just Mahmoud’s,” she said.

His unprecedented detention has sparked national outrage.

Further fueling the controversy, Abdalla, an American, gave birth to the couple’s first son in April while he remained behind bars.

Upon his release in Louisiana on Friday, Khalil addressed reporters briefly, saying he was excited to return to New York City and see his family.

“Although justice prevailed,” he said upon his release, “it’s long, very long overdue. And this shouldn’t have taken three months.”

“Trump and his administration, they chose the wrong person for this,” he added. “That doesn’t mean that there is a right person for this. There’s no right person who should be detained for actually protesting a genocide, for protesting their university, Columbia University.”

Assistant Homeland Security Secretary Tricia McLaughlin on Friday denounced the judicial order freeing Khalil and the judge who issued it.

“This is yet another example of how out of control members of the judicial branch are undermining national security,” McLaughlin said in a statement. “Their conduct not only denies the result of the 2024 election, it also does great harm to our constitutional system by undermining public confidence in the courts.”

The Trump administration claimed it had the authority to detain and deport the pro-Palestinian student activist, arguing that his presence in the U.S. threatened national security. Another charge against Khalil alleges that he omitted details about his work history and membership in organizations on his permanent residency application.

The government cited an obscure provision in the Immigration and Nationality Act of 1952 that gives Secretary of State Marco Rubio authority to “personally determine” whether a foreign national can remain in the U.S. on national security grounds.

An NBC News review of more than 100 pages of court filings found that prosecutors relied on unverified tabloid reports and anecdotal claims, raising doubts about the strength of their case for deporting Khalil.

Less than 10 minutes after Khalil, who has no criminal history, was released from the detention center in Jena, Louisiana, the Trump administration filed a notice of appeal. A lawyer representing Khalil vowed to fight the appeal.

Khalil helped lead student protests over the war in Gaza, where more than 55,000 people have been killed since Israel launched its war against Hamas. He also participated in negotiations with university officials at Columbia last year, when protests at the Ivy League school gripped national headlines for weeks and inspired similar demonstrations at universities around the world.

Some Jewish students at universities across the U.S. reported antisemitic incidents as the protest movement gained traction.

Khalil was the first of several foreign academics apprehended by immigration authorities in the first months of Trump’s second term.

Tufts University student Rümeysa Öztürk, a doctoral candidate from Turkey, was arrested outside her home in Somerville, Massachusetts, by immigration authorities on March 25. Viral street footage of her arrest showed Department of Homeland Security officials dressed in plain clothes surrounding Öztürk, grabbing her by the wrists and escorting her into an unmarked vehicle.

Mohsen Mahdawi, a 34-year-old graduate student at Columbia who was born in the West Bank, was apprehended by immigration authorities during his naturalization interview in Vermont.

Federal judges also ordered the release of both Öztürk and Mahdawi in recent weeks. Other notable cases include a Georgetown University professor who was detained by ICE and later released after a judicial order, and a Brown University professor who was deported to Lebanon.