
Russian President Vladimir Putin is reportedly growing frustrated by the challenges his military has faced from resilient Ukrainian forces, as there is now a concern that there could be a 'horrific' escalation of violence in Ukraine.
Many politicians and U.S. officials have expressed their fears because of the uncertainty of what Putin could do next.
"This is somebody that’s clearly been caught off guard by the size of the Ukrainian resistance," Sen. Mark Warner, D-Va. said on MSNBC. "He has isolated himself. He's not been in the Kremlin very much. ... You've got less and less inputs, and these inputs are from sycophants."
"I do worry that he’s been backed into a corner. I do worry that there is no obvious exit ramp," Warner added.
U.S. officials told NBC News that Putin has remained isolated away because of COVID-19 concerns, and has even "lashed out in anger" at those in his in inner circle on more than one occasion.
United States ambassador to the United Nations Linda Thomas-Greenfield emphasized the fear of escalating violence in Ukraine when she spoke on Wednesday and accused Russia of using certain weapons that are banned under the Geneva Convention.
"We have seen videos of Russian forces moving exceptionally lethal weaponry into Ukraine which has no place on the battlefield," Thomas-Greenfield said.
"That includes cluster munitions and vacuum bombs, which are banned under the Geneva Convention."
Paul Kolbe, former chief of the CIA's Central Eurasia division, told CNN's Erin Burnett that the use of these types of weapons could cause "horrific" damage to the entire area.
"The prospect of using these types of weapon -- whether cluster munitions or a thermobaric weapon -- in a civilized city, in a civilian area, is horrific to think about. It should shock the conscience of the entire world," Kolbe said.
Explosions near the Ukrainian capital of Kyiv on Wednesday night into Thursday morning lit the sky up, and forced people to take shelter immediately. There has already been a mass exodus of people from Ukraine, as over 1 million people have fled to neighboring countries for their safety.
Sen. Marco Rubio, R-Fla., told CNN's Jake Tapper what he fears Putin's next plan of attack could be, adding that he thinks the Russian leader will have to "create some new crisis."
"It's my personal opinion that this guy is going to have to create some new crisis, do something to reset the strategic balance and force everyone to the table with him," Rubio said. "It could be a combination of things, including a siege of Kyiv where 3 million people are being starved to death."
Michael Kofman, Director, Russia Studies at CNA, tweeted about the struggles Russia has had invading Ukraine and why he thinks the attacks will keep getting worse.
"What's next? Russia's political leadership is still not conceding their plan's failure, trying to take Kyiv quickly," Kofman tweeted. "But we're seeing them open up greater use of fires, strikes, and air power. Sadly, I expect the worst is yet ahead, and this war could get a lot more ugly."
Rubio also took to Twitter to share more of his thoughts on what Putin is going to do after his invasion of Ukraine has not gone as planned.
"DANGER #Putin's legitimacy built on image as the strong leader who restored #Russia to superpower after the disasters of the 90's Now the economy is in shambles & the military is being humiliated & his only tools to reestablish power balance with the West is cyber & nukes," Rubio tweeted.