The top Republican on the House Intelligence Committee said Russia's siege on Ukraine is a threat to the U.S. and told Fox News that America would need to get involved if nearby NATO members were attacked.

"What we're seeing is that Russia, under [Russian President Vladimir] Putin's leadership, has invaded a validly elected democracy, an independent nation, violating international law," Rep. Mike Turner told Fox News. "It's a threat to Europe and a threat to our NATO allies and therefore to the United States."

Russia invaded Ukraine on Thursday after amassing troops on the nation's border for months and reached the capital after one day of fighting.

RUSSIA INVADED UKRAINE: LIVE UPDATES

Putin "has openly stated that his goal is to reunite the geographical territory of the Soviet Union, and we should believe him," Turner said. "I don't think U.S. troops should be engaged directly, but we do play a role here that is very important."

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President Biden campaigned on the promise of standing up to Russia, tweeting in 2020 that "Vladimir Putin doesn't want me to be President. He doesn't want me to be our nominee. If you're wondering why – it's because I'm the only person in this field who's ever gone toe-to-toe with him." 

Turner told Fox News: "Vladimir Putin has very openly threatened the West and the United States. He specifically included in his exercises leading up to invading Ukraine a nuclear weapons exercise, which of course places the United States, our cities at risk."  

"Whenever you have a leader of a nation violating international law and openly threatening the world with weapons of mass destruction, we are entering a very difficult and very dangerous time," the Ohio Republican continued.

Thursday's attack marks the second time Putin invaded Ukraine under Biden's leadership. The Russian leader was sanctioned after he annexed Crimea in 2014 when Biden was vice president.

Ukraine military tanks

Ukrainian military drills with tanks on Feb. 7, 2022. 

"The Obama administration did not rise to that occasion after Crimea was invaded and annexed into Russia," Turner told Fox News.

Putin "sees an opportunity to be able to do this at the least cost," since the Biden administration showed "weakness" during the Afghanistan withdrawal and "mixed messages with respect to Ukraine itself," Turner said, noting that the Russian leader likely also reflected on the Obama administration's response to the previous invasion.

Putin of Russia

Russian President Vladimir Putin holds a video conference to address participants in a congress of the United Russia party marking the 20th anniversary of the party founding, in Moscow, Russia, Saturday, Dec. 4, 2021. (Mikhail Metzel, Sputnik, Kremlin Pool Photo via AP) ((Mikhail Metzel, Sputnik, Kremlin Pool Photo via AP)

PUTIN MAY HAVE OVERPLAYED HIS HAND BY INVADING UKRAINE, EXPERTS SAY: 'MASSIVE MISCALCULATION'

Nearly 140 Ukrainian soldiers and civilians had died as of early Friday, Ukrainian President Volodymyr Zelenskyy said in a video address.

The U.S. imposed new sanctions on Russia in response to the invasion. Turner agreed with the move. 

"Threatening the United States, threatening NATO, threatening our Western allies are only made good if he can continue to build and strengthen his military," Turner told Fox News. "Sanctions can have an impact on that."

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Russia launches missile

Russia launches intercontinental ballistic missile as part of nuclear drills on Feb. 19, 2022.  (RUSSIAN DEFENCE MINISTRY)

Sanctions on technology will hinder Russia from acquiring more military supplies and will hinder their cyberattacks, the Ohio Republican said.

Putin "needs technology from the West to do that, and we need to make certain that he doesn't get it," Turner told Fox News.