Russian Defense Ministry spokesperson Igor Konashenkov held another press briefing in which he accused NATO countries of committing war crimes.

Konashenkov claimed Thursday that mercenaries from the U.K. and U.S. are increasingly attacking Russian military medics who are accomplishing humanitarian missions in Ukrainian territory.

"Attacks on Russian medics and special medical vehicles by the Ukrainian nationalists and mercenaries that came earlier from the U.S., Britain and Europe to Ukraine have become more frequent over the past few days," Konashenkov said.

Konashenkov also denied reports that the Russian military had carried out a strike on a children’s hospital in Mariupol on Wednesday, dismissing reports on the matter as an "an information provocation staged by the Kyiv regime."

"The alleged airstrike that took place is a completely staged provocation in order to maintain the anti-Russian public outcry in the Western audience," he alleged.

Russian forces have destroyed nearly 3,000 military installations in Ukraine since the invasion began, Konashenkov claimed. In the last 24 hours, 68 installations, including two sites of the Ukrainian troop control system, 12 material and technical support centers and three Osa air defense missile systems, were obliterated, he said.

As part of her trip to Poland, Vice President Kamala Harris met with 7 people who fled the Russian invasion of Ukraine and some members of the U.S. embassy staff Thursday to discuss their experiences.

"I have invited in these very important people to join me for a conversation about their experiences, and also their thoughts about what we can do the United States and our allies in this region and around the world to support the many people that have been displaced through the necessity to flee Ukraine and the harm that it represents at this moment," Harris said to the group.

Harris thanked the group for meeting with her to share their experiences.

"The conversation we will have this afternoon will help inform me, the President of the United States, and the American people about what you have experienced, so that we can best support you and your family," Harris said to the group.

Before the press was ushered out, Harris sought to reassure the participants.

"We are here to support you and you are not alone. And I know there's so much about the experience that you've had that has made you feel alone. You are not alone," she pledged.

-ABC News' Molly Nagle

Belarusian President Alexander Lukashenko will travel to Russia on Friday for a meeting with his close ally and Russian counterpart, Vladimir Putin.

The two leaders will meet in Moscow where they "will discuss key issues concerning bilateral relations, the development of union cooperation and economic cooperation in conditions of sanctions pressure," according to the Pool of the First Man channel on Telegram, which is reportedly linked to Belarusian state media.

"The situation in the region and in Ukraine is on the agenda as well," the channel said.

Western Union announced Thursday that it is suspending its operations in Russia and close ally Belarus amid the Russian invasion of neighboring Ukraine.

The Denver-based money-transfer and payments company said in a statement that it "stands with the world in condemning the unprovoked and unjustified invasion of Ukraine."

"All of us share the shock, disbelief, and sadness around this tragedy and humanitarian disaster," the company added. "Our hearts go out to the people of Ukraine and to our colleagues, customers, agents, and partners who have been impacted."

Company leadership have engaged in extensive dialogue with a wide variety of stakeholders "in an earnest effort to arrive at the right decision regarding our services in Russia and Belarus," according to Western Union.

"We have thoroughly evaluated internal and external considerations, including the consequences for our valued teammates, partners, and customers," the company said. "Ultimately, in light of the ongoing tragic impact of Russia’s prolonged assault on Ukraine, we have arrived at the decision to suspend our operations in Russia and Belarus."

-ABC News' Christine Theodorou