Iowa Gov. Kim Reynolds implied Russia's attack on Ukraine is connected to a lack of leadership from President Joe Biden in the Republican response to the State of the Union address, saying Biden has "sent us back in time" to the 1970s and '80s, when the "Soviet army was trying to redraw the world map."

Reynolds said Biden has failed on his promise to make America respected around the world once more and criticized Biden for the lead-up to the invasion, including waving sanctions against Russia and "focusing on political correctness."

"Weakness on the world stage has a cost," Reynolds said. "... We can’t project strength abroad if we’re weak home."

In his first State of the Union address, President Joe Biden began by discussing the war in Eastern Europe and condemning Russian President Vladimir Putin’s invasion of Ukraine.

Biden invoked the strength of the Ukrainian people amid the attack, lauding the civilians who took up arms to defend their country and highlighting the work Ukrainian Ambassador to the U.S. Oksana Markarova has done on behalf of her people.

"She’s bright. She’s strong, and she’s resolved," Biden said as first lady Jill Biden hugged Markarova.

Many lawmakers in attendance showed their support for Ukraine by wearing color-coordinated outfits and lapel pins in blue and yellow.

Biden described the invasion as "premeditated and totally unprovoked," vowing, alongside NATO allies, to hold Putin accountable with sanctions on the Russian economy and Putin and the oligarchs themselves.

"When dictators do not pay a price for their aggressions, they cause more chaos," Biden said. “They keep moving.”

Biden announced that American airspace would be closed to all Russian flights and pledged $1 billion in direct assistance to help "ease suffering" in Ukraine.

The president also "made clear" that while American forces would not go fight in Ukraine, he has mobilized the military to protect NATO countries.

"The United States and our Allies will defend every inch of territory that is NATO territory with the full force of our collective power," he said.

-ABC News' Julia Jacobo and Ben Gittleson

President Joe Biden in his State of the Union address announced the U.S. will ban Russian flights from its airspace, joining Canada and the European Union, which issued bans on Russian planes in their respective airspaces over the weekend.

"Tonight I am announcing that we will join our allies in closing off American air space to all Russian flights -- further isolating Russia -- and adding an additional squeeze on their economy," Biden said.

The ban will apply to "operations of all aircraft owned, certified, operated, registered, chartered, leased, or controlled by, for, or for the benefit of, a person who is a citizen of Russia," according to the Federal Aviation Administration. "This includes passenger and cargo flights, and scheduled as well as charter flights, effectively closing U.S. air space to all Russian commercial air carriers and other Russian civil aircraft."

The ban will be "fully effective" by the end of the day Wednesday, the FAA said.

-ABC News' Ben Gittleson

While all eyes in Washington are on President Joe Biden's State of the Union address, some lawmakers have been working the phones to rally support at the United Nations for a resolution before the General Assembly to condemn Russia's invasion of Ukraine and call for a peaceful resolution.

Working with the United States Mission to the United Nations, Democrats on the House Foreign Affairs Committee have identified more than a dozen countries to target and called for ambassadors and key diplomats to leverage relationships to build more support for the nonbinding resolution.

"This has been a way for Congress to really play an important role working with the executive branch in getting this done and showing the world that Russia's actions are illegal and should be condemned," Rep. Joaquin Castro, D-Texas, a senior member of the committee that is leading the effort, told ABC News.

The vote "is an opportunity for countries to take a stand, and it's especially a chance for the United States to demonstrate leadership among the nations of the world," he said.

"President Biden and his administration, and now Congress, I believe, have demonstrated our ability to marshal our allies to condemn something the world has worked for decades to root out -- which is a sovereign nation invading another."

Republicans have also been working to build support for the measure in the General Assembly, Castro said.

-ABC News’ Ben Siegel

Russia's Foreign Ministry claimed U.S. military intelligence launched a massive campaign to recruit contractors from private military companies to send to Ukraine.

"They recruit primarily those employed by Academi, CUBIC and DynCorp [International]," Russian Defense Ministry spokesperson Igor Konashenkov said in a press briefing on Thursday.

Foreign mercenaries who have arrived in Ukraine are performing acts of sabotage and attacking Russian convoys of motor vehicles and aviation, Konashenkov said.

"Foreign mercenaries who earlier arrived in Ukraine are carrying out acts of sabotage and raids on Russian convoys of [military] vehicles and materiel supplies, and on the aviation supporting them," Konashenkov said.

Konashenkov claimed Britain, Denmark, Latvia, Poland and Croatia have legally permitted their citizens to take part in Ukraine hostilities and that the command of the French Foreign Legion plans to send its ethnic Ukrainian troops to aid the Kyiv regime.

Mercenaries from other countries in Ukraine will not receive prisoner-of-war status and will be subject to criminal liability, Konashenkov said.

"I want to officially emphasize that all mercenaries sent by the West to help the Kyiv nationalist regime are not combatants under international humanitarian law. They are not entitled to POW status," Konashenkov said.

Russia said it hopes its current talks with Ukraine on Belarusian soil will soon lead to a peaceful settlement, Russian Foreign Ministry spokesperson Maria Zakharova said.

"We hope the [talks] will lead to a swift conclusion of this situation, the restoration of peace in Donbas, and the return of all peoples of Ukraine to a peaceful and equitable life," she told a briefing in Moscow on Thursday.

- ABC News' Tanya Stukalova