President Joe Biden called the arrest warrant issued for Russian President Vladimir Putin Friday by the International Criminal Court "justified," though acknowledged it might not have strong teeth.

"Well, I think it's justified," Biden told reporters Friday evening. "But the question -- it's not recognized internationally, by us either. But I think it makes a very strong point."

In a earlier statement on the warrant, the White House said it supports "accountability for perpetrators of war crimes."

"There is no doubt that Russia is committing war crimes and atrocities in Ukraine, and we have been clear that those responsible must be held accountable," National Security Council spokesperson Adrienne Watson said in the statement.

-ABC News' Cheyenne Haslett and Davone Morales

Turkey is beginning the process of ratifying Finland's application to join NATO, Turkish President Recep Tayyip Erdogan said Friday, 10 months after both Finland and Sweden applied to become NATO members in the wake of Russia’s invasion of Ukraine.

"At a critical time for our security, this will make our alliance stronger and safer," NATO Secretary General Jens Stoltenberg said in a statement.

The breakthrough came as Finnish President Sauli Niinisto was in Ankara, Turkey, to meet with Erdogan.

Erdogan said Finland fulfilled its part of the agreements and therefore he saw no reason to further delay the ratification process. Erdogan did not provide an update on Sweden's bid.

National security adviser Jake Sullivan said in a statement, "We encourage Türkiye to quickly ratify Sweden’s accession protocols as well. In addition, we urge Hungary to conclude its ratification process for both Finland and Sweden without delay. … The United States believes that both countries should become members of NATO as soon as possible."

-ABC News' Will Gretsky

The International Criminal Court has issued an arrest warrant for Russian President Vladimir Putin, saying in a statement Friday that Putin is "allegedly responsible for the war crime of" unlawfully deporting children from occupied areas of Ukraine and bringing them to Russia.

The ICC also issued an arrest warrant for Maria Lvova-Belova, Russia's presidential commissioner for children's rights, alleging she carried out the same war crime.

Russian Foreign Ministry spokeswoman Maria Zakharova said in a statement that the arrest warrants "have no meaning for the Russian Federation" and "are legally null and void."

Andriy Yermak, head of the Office of the President of Ukraine, tweeted that the arrest warrants are "just the beginning."

Russia has committed a "wide range of war crimes" and possible crimes against humanity in Ukraine, according to a new United Nations-backed investigation.

"The body of evidence collected shows that Russian authorities have committed a wide range of violations of international human rights law and international humanitarian law in many regions of Ukraine and in the Russian Federation," the human rights report by the Independent International Commission of Inquiry on Ukraine stated. "Many of these amount to war crimes and include willful killings, attacks on civilians, unlawful confinement, torture, rape, and forced transfers and deportations of children."

Additionally, Russian attacks on Ukraine's energy-related infrastructure and use of torture "may amount to crimes against humanity," the report concluded.

The commission said it conducted interviews with nearly 600 people, inspected graves, destruction and detention sites and consulted satellite imagery and photographs as part of its investigation.

Ukrainian Defense Minister Oleksii Reznikov said Friday the military is "ready" to launch a counteroffensive against Russian forces.

"It's up to the general staff and the command," Reznikov said during a press briefing in Kyiv. "We will do it as soon as there is God's will, the weather and the commanders' decision."

Ukraine has received Patriot missile defense systems from the United States as well as Germany and the Netherlands. The Ukrainian military has been trained on how to use the systems and "mastered" them within weeks, according to Reznikov.

"The exact number of batteries, I'm sorry, I won't say," he added. "Let the enemy guess."

Meanwhile, Ukrainian Foreign Minister Dmytro Kuleba urged the world not to consider or call the anticipated counteroffensive "a decisive battle." Speaking at a press conference in Odesa on Friday, Kuleba said the decisive battle is the one that will lead to the liberation of all occupied Ukrainian territories.

-ABC News’ Will Gretsky