Updated

President Biden on Saturday called Russian President Vladimir Putin "a butcher" after he met with displaced Ukrainian mothers and their children in Warsaw, Poland. 

It's the latest name that Biden has used for Putin. He previously called Putin a "war criminal," and in 2021 called him a "killer."

A Kremlin spokesman indicated that the latest Biden comment makes repairing relations between Russia and the U.S. more difficult, according to Russian state media.

RUSSIA INVADES UKRAINE: LIVE UPDATES

Putin’s deadly invasion into Ukraine more than four weeks ago has led to the greatest security crisis in Europe since World War II with more than 3.7 million refugees having fled the war-torn nation. 

The United Nations Human Rights Office estimates that roughly 1,035 civilians in Ukraine have been killed with another 1,650 injured – though in reality these figures are expected to be much higher.

President Biden meets with Ukrainian refugees and humanitarian aid workers during a visit to PGE Narodowy Stadium, Saturday, March 26, 2022, in Warsaw. (AP Photo/Evan Vucci)

President Biden meets with Ukrainian refugees and humanitarian aid workers during a visit to PGE Narodowy Stadium, Saturday, March 26, 2022, in Warsaw.  (AP Photo/Evan Vucci)

RUSSIA INVADES UKRAINE: LIVE UPDATES

The State Department on Friday said that the U.S. government assesses that nearly 10,000 Russian soldiers have been killed since the onslaught of the invasion and more than 15,000 have been injured.  

Poland has accepted the vast majority of the Ukrainian refugees and is hosting more than 2.2 million displaced Ukrainians. 

Romania has taken in nearly 580,000 people while Moldova, Hungary, Russia, Slovakia and Belarus have received another 888,000 refugees. 

The U.S. has agreed to welcome 100,000 Ukrainian refugees and Biden on Saturday urged all NATO nations to open their borders to those fleeing the war.

"We do acknowledge that Poland is taking on a significant responsibility that I don't think should just be Poland and should be the whole world — all of NATO's responsibility," Biden told Polish leaders.

russia ukraine war

A Ukrainian evacuee hugs a child in the train station in Przemysl, near the Polish-Ukrainian border, on March 22, 2022, following Russia's military invasion launched on Ukraine. - The UN says almost 3,6 million people have fled Ukraine since the Russian invasion, with more than two million of them heading to neighbouring Poland.  (Photo by ANGELOS TZORTZINIS/AFP via Getty Images)

RUSSIA 'PRIORITIZING' EASTERN UKRAINE AS GROUND FORCES REMAIN STALLED, REINFORCEMENTS COMING FROM GEORGIA: DOD

The president met with Ukrainian refugees who are being housed at the PGE Narodowy Stadium in Warsaw, which is capable of holding up to 58,000 people. 

Ukrainian mothers spoke to Biden while holding their children and explained their fury over Putin’s illegal incursion.

"We Ukrainian mothers are ready to strangle him with our bare hands," one woman said, explaining that her husband and son stayed behind to fight. 

Security officials have warned they believe Putin’s strategy in Ukraine has changed due to his inability to make ground advances.

Russian forces have pummeled Ukrainian cities and towns with missile fire as ground forces remain stalled across the country. 

Ukrainian soldiers and firefighters search in a destroyed building after a bombing attack in Kyiv, Ukraine, Monday, March 14, 2022. (AP Photo/Vadim Ghirda) (AP Photo/Vadim Ghirda)

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Buildings sheltering noncombatants, including women, children and the elderly, have increasingly been hit by Russian shelling, and Putin’s forces have been accused of war crimes for intentionally targeting civilians.

The president on Saturday was asked what he thought of Putin’s change in strategy to which he answered, "I’m not sure he has."