Russia claims that Biden's "war criminal" accusation has brought relations to the brink of collapse.

• The Russian government stated that it informed the U.S. Ambassador John Sullivan that President Joe Biden's classification of Russian President Vladimir Putin as a "war criminal" has brought "Russian-American relations to the brink of collapse."
• Biden publicly labeled Putin a "war criminal" for the first time on Wednesday, stating that he believes the Russian leader is responsible for the attacks on Ukraine.
• As Russia approaches the one-month mark of its unprovoked invasion of Ukraine, the diplomatic breakdown becomes increasingly evident.

On Monday, the Russian Ministry of Foreign Affairs summoned U.S. Ambassador John Sullivan in Moscow to protest President Joe Biden's decision to label Russian President Vladimir Putin a "war criminal."

According to a statement from the Foreign Ministry, translated by NBC News, Sullivan was informed that Biden's accusation had brought "Russian-American relations to the brink of collapse."

Biden publicly labeled Putin a "war criminal" for ordering Russia's invasion of Ukraine on Wednesday, marking the first time he has used that term to describe the Russian leader.

The International Criminal Court's top prosecutor met virtually with Ukrainian President Volodymyr Zelenskyy and other top officials to discuss the ongoing investigation into possible war crimes by Russia.

On Monday, CNBC did not receive an immediate response from a State Department spokesperson when requesting a comment.

The US Embassy in Moscow tweeted that Sullivan met with Russian diplomats to request consular access to US citizens imprisoned in Russia, including those in pretrial detention.

Brittney Griner, an American WNBA star player, is currently being held in pretrial detention in Moscow due to accusations of drug smuggling. Despite this, the American Embassy did not mention Griner's name in a recent tweet.

In 2021, Biden asked Sullivan, a Trump-era appointee, to remain in his position.

The diplomatic breakdown occurs as Russia approaches the one-month mark of its unprovoked invasion of Ukraine, which began on Feb. 24.

The initial Russian infantry advance has largely stalled outside of the country's major cities due to fierce Ukrainian resistance. As a result, the Kremlin has shifted tactics from a quick land war to a conflict of attrition marked by the shelling of residential areas in an effort to wear down and demoralize the nation.

Jen Psaki, the White House press secretary, stated later that Biden's comments were sincere and based on the news he had seen about the "barbaric actions" of a "brutal dictator."

The legal process to determine if Putin has violated international law and committed war crimes is currently underway at the State Department, as Psaki noted.

Top officials in the Biden administration have openly claimed that Putin is a war criminal and that Russia is committing war crimes in Ukraine.

The day following Biden's remark, Blinken concurred with the president's evaluation of Putin, stating, "Personally, I agree."

Blinken stated that intentionally targeting civilians is a war crime, but after the devastation of the past three weeks, he finds it hard to believe that the Russians are not doing the same.

Secretary of State Antony Blinken concurred with the president's evaluation of Putin.