Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

The United States and its G-7 allies announced a new round of sanctions on Sunday against Russia, including some aimed at crippling three of Russia's largest state-controlled television stations.

The new sanctions were announced after leaders from the G-7 group held a virtual summit with Ukrainian President Volodymyr Zelenskyy.

"Putin has failed in his initial military objective to dominate Ukraine -- but he has succeeded in making Russia a global pariah. Today, the United States, the European Union and G7 committed to ratchet up these costs by collectively taking further measures, consistent with each partner’s respective legal authorities and processes,” reads a fact sheet of the new measures released by the White House.

Sanctions will be imposed against Russia's Channel One, Russia-1 and the NTV Broadcasting Company, including cutting off the outlets' access to technology like video cameras, microphones, lighting equipment and software services, according to the fact sheet. Advertising dollars derived from the United States will also be prohibited from funding the companies.

“Russia can try to produce these components domestically but the idea here is to make that commercially difficult, unprofitable, put more of the burden on the Russian state. We’re not going to be in the business of helping them broadcast the lies and deceit that you hear from Putin every day,” a senior Biden administration official said.

The entire G-7 also announced it is committed to phasing out or banning the import of Russian oil.

Additionally, the new sanctions prohibit anyone from the United States from providing accounting, trust, corporate formation and management consulting services to members of Russian Federation.

The United States is also imposing about 2,600 visa restrictions for Russian and Belarussian officials, and creating a new visa restriction policy for Russian Federation military officials and “Russia-backed” or “Russia-installed” officials believed to be involved in human rights abuses, violations of international humanitarian law or corruption in Ukraine.

New restrictions are to be imposed on wood products, industrial engines, motors, and bulldozers, according to Biden administration officials.

The administration is also sanctioning Promtekhnologiya LLC, a Russian company that manufactures rifles and weapons Russian forces have used in Ukraine.

In addition to the new sanctions, the U.S. Nuclear Regulatory Commission is suspending licenses for exports of special nuclear material, byproduct material and deuterium, or heavy hydrogen, to Russia.

ABC News' Armando Garcia

First lady Jill Biden, in Eastern Europe to show American support for its NATO allies, made a surprise visit to Ukraine Sunday, where she met with that nation's first lady.

Biden's motorcade crossed into Ukraine from Slovakia, where earlier in the day she toured refugee aid stations.

In Ukraine, she visited a public school in the city of Uzhhorod, where she met privately with the first lady of Ukraine, Olena Zelenska, for about half an hour.

"I thought it was important to show the Ukrainian people that this war has to stop," Biden told reporters following the visit. "And this war has been brutal. And that the people of the United States stand with the people of Ukraine."

"We understand what it takes for the U.S. first lady to come here during a war where the military actions are taking place every day, where the air raid sirens are happening every day, even today," Zelenska said through a translator. "We all feel your support. We all feel the leadership of the U.S. president."

"We would like to note that Mother’s Day is a very symbolic day for us," Zelenska added. "Because we also feel your love and support during such an important day."

-ABC News' Armando Garcia

Emergency responders were searching on Sunday for dozens of missing civilians after Russian forces struck a school building being used as a shelter in Bilohorivka, a village in eastern Ukraine, a local official said.

About 90 civilians had taken shelter in the building before it was destroyed on Saturday, Serhiy Haidai, regional governor of Luhansk in eastern Ukraine, said.

About 30 people had been rescued and two bodies were found in the rubble, the local emergency services said. Rescue efforts resumed at dawn on Sunday, Haidai said on social media.

Russia will hold its annual Victory Day on Monday, a national holiday under Russian President Vladimir Putin that marks the Soviet victory over Nazi Germany in World War II.

From the start, the Kremlin had hoped to use Victory Day to celebrate its own triumph in Ukraine, but Russia’s offensive to take Donbas has badly stalled. Instead, the Kremlin is expected to use the day to try to galvanize support among Russians for the war.

The day is being watched closely because how Putin sells the war could give a sense of how long the Kremlin wants to fight.

Ukraine, Western countries and many experts fear Putin might use Victory Day to declare a national mobilization -- without which many military analysts doubt Russia can achieve even its already curtailed goals in Ukraine.

If Putin does not use Victory Day to declare a general mobilization, that could suggest the Kremlin doesn’t believe it has the political strength at home right now to do so.

-ABC News' Patrick Reevell