Biden calls Putin a 'murderous dictator' and 'pure thug,' doubling down on his criticism of the Russian president

• Biden on Thursday showed no sign of backing away from his harsh criticism of Vladimir Putin.
• "Putin's brutality and what he's doing and his troops are doing in Ukraine is just inhumane," Biden said.

President Joe Biden refused to back away from harsh critiques of Vladimir Putin on Thursday even after the Kremlin warned the White House about the stakes of one president calling another a "war criminal."

"Now you have Ireland and Great Britain ... standing together against a murderous dictator, a pure thug, who is waging an immoral war against the people of Ukraine," Biden said during a speech at the annual St. Patrick's Day luncheon on Capitol Hill where he applauded Ireland for standing with the West in opposing Russia's war.

Earlier in the day, Biden also called out Putin by name.

"Putin's brutality and what he's doing and his troops are doing in Ukraine is just inhumane," Biden said during a meeting with Taoiseach Micheál Martin, the prime minister of Ireland. Martin appeared virtually after testing positive for COVID-19.

The Kremlin said it was "unacceptable and unforgivable" for Biden to call Putin a "war criminal." Kremlin spokesperson Dmitry Peskov said it was "unforgivable rhetoric on the part of the head of a state whose bombs have killed hundreds of thousands of people around the world," according to Russian state news agency TASS.

White House press secretary Jen Psaki also dismissed the Kremlin's attempts to shift blame.

"That's pretty rich coming from a country whose actions are unforgivable in the eyes of the global community," Psaki told reporters.

Formal investigations are underway into whether Russian forces are committing war crimes in Ukraine. But the wide coverage of the war has captured scores of apparent crimes from bombing civilian areas to targeting nuclear power plants. On Wednesday, 10 civilians were killed in Chernihiv while waiting in a breadline.

Secretary of State Antony Blinken echoed Biden's belief that war crimes have occurred in Ukraine.

"Personally, I agree," Blinken told reporters when asked about Biden's view.

Defense Secretary Lloyd Austin said on Thursday that he too has been "shocked by the brutality we continue to witness day in and day out."

"These attacks that we've seen most recently appear to be focused directly on civilians," Austin said, speaking alongside Slovakia's defense minister Jaroslav Naď. The Pentagon head stopped short of calling the acts war crimes.