Russian forces have purportedly taken control of the settlement of Metyolkino in the Donbas region of Eastern Ukraine, according to Russian military officials.

The Russian Federation Armed Forces said Metyolkino was "liberated" by units from the People's Militia of the Lugansk People's Republic with the help of the Russian army.

Russian officials claimed several units of the Armed Forces of Ukraine fighting near Lisichansky in the Donbas region "are abandoning the operation area due to low moral and psychological condition, as well as lack of munitions and logistics supply."

There was no immediate comment from Ukrainian officials.

Meanwhile, Russian troops continued to launch attacks on military targets across Ukraine, according to Russian officials.

The attacks included long-distance sea-based missile attacks on Ukrainian troops in the village of Shirokaya Dacha in the Central Ukraine, according to Russian officials. The attack was launched while Ukrainian military commanders were meeting in the village and "resulted in eliminating more than 50 generals and officers of the AFU (Armed Forces of Ukraine)," Russian officials said in a statement.

Long-range missile attacks over the past 10 days have destroyed 10 155-mm howitzer cannons and 20 armored combat vehicles Russian military officials said were sent to Ukrainian forces by Western countries. One Russian missile strike destroyed a transformer plant in Nikolayev in Southern Ukraine, according to Russian officials,

Retired Marine Capt. Grady Kurpasi has been identified as the third American volunteer fighter missing in Ukraine.

Kurpasi’s wife Soohee Kim said she last heard from him in late April. He left Wilmington, North Carolina, on March 7 bound for Ukraine, but did not know how long he would be there, she said.

Kim confirmed she is in regular contact with the Department of State and hears from them almost daily.

Alexander Drueke and Andy Huynh are also two American volunteer fighters reported missing in Ukraine.

-ABC News’ Luis Martinez and Vera Drymon

The United Kingdom announced a new wave of sanctions on Thursday targeting Russians involved in the barbaric treatment of children in Ukraine.

Maria Lvova-Belova, Russia's Children Rights Commissioner, tops the new list of sanctioned individuals for her alleged involvement in the forced transfer and adoption of Ukrainian children. She has been accused of enabling 2,000 vulnerable children being violently taken from the Luhansk and Donetsk regions and orchestrating a new policy to facilitate their forced adoptions in Russia.

“Today we are targeting the enablers and perpetrators of [Russian President Vladimir] Putin’s war who have brought untold suffering to Ukraine, including the forced transfer and adoption of children,” U.K. Foreign Secretary Liz Truss said in a press release.

More than 900 children were injured in Ukraine as a result of the full-scale armed aggression by the Russian Federation, according to the Ukrainian Prosecutor General’s latest report. Over 320 children were killed and more than 580 were injured.

These figures are far from being final, with more information slowly trickling in from places of active hostilities, as well as the temporarily occupied and liberated territories.

The UK's sanction list also includes Patriarch Kirill, the head of the Russian Orthodox Church, for his support and endorsement of Putin’s war.

Several members of Putin's political elite, along with four Military Colonels from a unit known to have killed, raped and tortured civilians in the Ukrainian town of Bucha, appear on the list too.

“Putin’s allies continue to choose to turn a blind eye to alleged war crimes and support his bloody offensive,” the U.K. government said. With Putin’s aggression reaching beyond Ukraine as Russian exports fuel conflict across the globe, the official press release read, the new sanctions also hit Myanmar’s military Junta.

The Junta relies heavily on Russian air assets and limiting it will cut Putin off from profiting from sales that fund his war machine, the U.K. said.

-ABC News' Edward Szekeres, Yuriy Zaliznyak, Yulia Drozd and Max Uzol

Russia's invasion of Ukraine has already engaged around 330,000 Russian personnel, Brigadier General Oleksiy Hromo of the General Staff of the Ukrainian Armed Forces told local media on Thursday.

“[Russian] groups at various axes are close to 150,000 strong. If we add their air and sea components, there are about 220,000 military personnel,” Hromo said. Russia also deployed “units of the national army combat reserve, the federal service of guard forces, and mobilization units,” the Brigadier General added.

Hromo's sobering account came on the back of claims made by a top Ukrainian official earlier on Wednesday that revealed mounting Ukrainian casualties. Up to 1,000 Ukrainian soldiers are being killed or wounded each day in the Donbas region of eastern Ukraine, with 200 to 500 killed on average and many more wounded, said David Arakhamia, who heads the presidential faction in the Ukrainian parliament.

In early June, Ukrainian President Volodymyr Zelenskyy said daily fatalities among Ukrainian ranks at the Donbas front were between 60 to 100 troops.

Arakhamia, one of Zelenskyy's closest advisers who oversees Ukraine's stalled negotiations with Russia, has been leading a Ukrainian delegation in Washington this week in a bid to lobby the Biden administration and Congress.

Arakhamia's team want to see the pace of weapons shipments increased and is pushing for a designation of Russia as a state sponsor of terrorism.

-ABC News' Edward Szekeres, Yuriy Zaliznyak, Yulia Drozd and Max Uzol

Russian forces are advancing toward the city of Lysychansk in eastern Ukraine's Luhansk region, putting the Lysychansk-Severodonetsk pocket "under increasing pressure," the British Defense Ministry said. Some Ukrainian forces have withdrawn from Lysychansk, "probably to avoid being encircled," the officials said.

The Ukrainian army claims Ukrainian soldiers stopped the Russian offensive in the southern outskirts of Lysychansk on Thursday, inflicting losses and forcing them to retreat, and that to resume the offensive, Russian forces put forward reserves.

-ABC News' Fidel Pavlenko