Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

Pentagon spokesman John Kirby told reporters Friday that the U.S. doesn't have "firm indications" that Russia is planning a so-called "false flag" operation to justify use of chemical or biological weapons, but that it is something officials think "could happen that we want to watch out for."

"We're watching this as closely as we can," Kirby said during a briefing, adding that he didn't have anything specific to report on Russian chem-bio capabilities inside Ukraine.

"We continue to watch for the potential -- and I want to stress the word potential -- that they could be banging this drum with the intent of creating some sort of false flag event that they could use as an excuse to escalate the conflict even more," he continued. "I don't have any specific indication now to talk about, but it is something we're concerned about."

Kirby described how Russia possesses a biochemical weapons program and has a "reputation" for using such weapons in the past.

As for concerns that Russia was planning a false flag of a Ukrainian attack in Belarus Friday, Kirby said he had seen the claims by the Ukrainian Defense Ministry but had nothing to corroborate them.

Ukraine's air force claimed Friday that Russia did carry out an alleged false flag airstrike in a Belarusian village near the border with Ukraine.

-ABC News' Luis Martinez

Ukrainian technicians have started repairing damaged power lines in an attempt to restore external electricity supplies to the site of the Russian-controlled Chernobyl nuclear power plant that were entirely cut earlier in the week, according to International Atomic Energy Agency Director General Rafael Mariano Grossi.

Ukraine’s regulatory authority said work began Thursday and technicians had succeeded in repairing one section, but off-site electrical power was still down, indicating there was still damage in other places.

Emergency diesel generators have been providing backup power to the site since Wednesday, and the regulator has reported that additional fuel had been delivered to the facility, the IAEA said.

The regulator lost communications with the site on Thursday and, as a result, it cannot provide information to the IAEA about the radiological monitoring at the facility, according to Grossi.

The regulator is still receiving information about the situation there through senior off-site management of the plant, Grossi said.

The plant's disconnection from the grid will not have a critical impact on essential safety functions at the site, however, staff is facing increasingly difficult conditions.

At least 211 technical personnel and guards have been living at the site for more than two weeks, and there is concern about the availability of food reserves, the regulator said.

The IAEA said eight of the country’s 15 reactors remained operating. Radiation levels at the locations were normal, the IAEA said.

-ABC News' Zoe Magee

Russian forces have kidnapped the mayor of the southern Ukrainian city of Melitopol, which is currently under Russian occupation, according to a Ukrainian official.

Melitopol has been occupied since the first days of the invasion, but its mayor, Ivan Fedorov, had insisted it remained part of Ukraine. He was taken from his office by Russian troops Friday afternoon, according to Kirill Timoshenko, an advisor to Ukraine’s president.

Timoshenko posted a CCTV video allegedly showing Fedorov being led out of the building by a large group of heavily armed Russian soldiers.

Local people have been protesting the Russian occupation almost everyday, marching in the city with Ukrainian flags and confronting Russian soldiers.

A local woman who has taken part in the protests, Tatiana Kumok, in a phone call with ABC News, said Russian riot police surrounded the central square and tried to prevent protests last week.

Kumok said that local TV has been switched to Russian channels and that a new Russian "police force" has been deployed on the streets.

Kumok said she fears that Russia plans to permanently occupy Melitopol, even if Russia eventually reaches a deal with Kyiv. She said they have been told they will be given Russian passports.

-ABC News' Patrick Reevell

The Russians are flying an average of 200 sorties, military units, per day, while the Ukrainians are only flying about 10, a senior U.S. defense official told reporters Friday.

The official said much of the airspace above Ukraine is heavily guarded by both Ukrainian and Russian surface-to-air missiles, making air operations risky for both sides, but Russian aircrafts do not have to enter that airspace to do damage.

"You can launch cruise missiles from aircraft from a great distance away. And if your target is relatively close, you don't need to enter the airspace," the official said.

The Ukrainians have 56 functioning fighter jets available to them now and they are only flying them five to 10 hours a day, according to the official.

Noting Russia's vast umbrella of anti-aircraft capability over Ukraine and its larger air force, the official repeated some of the arguments we heard from the Pentagon earlier this week about the relative ineffectiveness of sending more aircraft to Ukraine.

"It makes little sense to us that additional fixed-wing aircraft is going to have somehow solve all these problems," the official said.

The official added, "What they need are surface-to-air missile systems, they need [man-portable air-defense systems], they need anti-armor, they need small arms and ammunition and they need these drones, because that's what they're using with great effect. And so that's what we're focused on."

Ukrainian forces are using drones to "terrific effect," especially against Russian ground movements, according to the official.

"They're trained on how to use them [and] they can fly below radar coverage by the Russians," the official said.

Russian troops have not moved any closer to Kyiv from the northwest since yesterday, still approximately 9 miles from city center. But, the U.S. has seen rear elements move up closer to those advance troops. Russians advancing on the capital from northeast are now 12 to 19 miles out, according to the official.

Mariupol is under increasing pressure on Friday as it is surrounded from the northeast and southwest, and is under heavy bombardment, the official said. But, Ukrainians are fighting back there.

Russians are "closing in on" Kharkiv, but the city is well defended and hasn't been taken yet, according to the official.

The Russians have now launched nearly 810 missiles against Ukraine -- almost half have been fired from within Ukraine using mobile platforms. The rest have been fired from Russia, Belarus, and a small number from the Black Sea, according to the official.

-ABC News' Matt Seyler