Biden called on Congress to send him a bipartisan national security bill amid Russia's ongoing war in Ukraine.

"If the United States walks away, it will put Ukraine at risk. Europe is at risk, the free world will be at risk," he said.

Biden also had a message for Russian President Vladimir Putin: "We will not walk away," he said to applause.

"We will not bow down! I will not bow down! In a literal sense, history is watching," Biden said.

Many Republicans have been increasingly skeptical of foreign aid to Ukraine versus spending on domestic priorities like the southern border. Biden and the GOP have not been able to agree on new immigration changes, despite a Biden-backed deal in the Senate.

Biden took his first jab at Trump of the night as he called on Congress to provide further assistance to Ukraine in its fight against Russian invaders.

"Ukraine aid is being blocked by those who want to walk away from our world leadership," he said. "It wasn't long ago, when a Republican president named Ronald Reagan thundered, 'Mr. Gorbachev, tear down this wall.'"

Biden continued, "Now, my predecessor, a former Republican president, tells Putin, 'Do whatever the hell you want.' That's a quote. The former president actually said that bowing down to a Russian leader. I think it's outrageous, it's dangerous and it's not acceptable."

Biden dubbed the current time an "unprecedent moment" in America, drawing parallels to his speech Thursday with that of former President Franklin Delano Roosevelt in 1941, right before the U.S. entered World War II.

"Tonight, I come to the same chamber to address the nation. Now, it's we who face an unprecedented moment in the history of the union. And yes, my purpose tonight is to wake up the Congress and alert the American people this is no ordinary moment either," Biden said.

The president warned that "freedom and democracy under assault" both "at home and overseas at the very same time," pushing for aid to Ukraine as it works to fight off Russia's invasion -- adding a warning as Congress proves unable to agree on a bill to send aid to Kyiv.

"If anybody in this room thinks Putin will stop at Ukraine, I assure you he will not," Biden said.

While Biden entered the U.S. Capitol House chambers for his State of the Union address, Secretary of Education Miguel Cardona was announced as the "designated survivor."

The designated survivor is a Cabinet member chosen to remain physically away from the president and vice president in case of an emergency or an attack during the State of the Union.

Cardona will go to an undisclosed location for the duration of the address.

Republicans plan to keep an empty seat in memoriam of Laken Riley, a 22-year-old nursing student who was killed on the University of Georgia's Athens campus last month.

Rep. Mike Collins, R-Ga., said he invited Riley's parents to be guests at the State of the Union though "they have chosen to stay home as they grieve the loss of their daughter."

Biden's address comes hours after the House passed the Laken Riley Act, which would require detention of any unauthorized migrant who commits burglary or theft.

The suspect charged in Riley's killing, Jose Antonio Ibarra, unlawfully entered the U.S. near El Paso, Texas, in September 2022 and was paroled and released for further processing, U.S. Immigration and Customs Enforcement said following his arrest in Georgia.

ICE said that Ibarra was subsequently arrested by New York City police in 2023 and released before federal officials could ask for his detention. The NYPD has said there is no arrest on file.

The Laken Riley Act passed the House 251-170, with 37 Democrats voting for it. Some opposing it believe Republicans are using Riley's death for their own political gain to place blame on the Biden administration's border policies as polling shows immigration is a top issue for some voters.