Russia's Foreign Minister Sergei Lavrov said Friday that any foreign supplies to Ukraine containing military equipment will be considered "legitimate targets" for Russian strikes.

"We clearly said that any cargo moving into the Ukrainian territory which we would believe is carrying weapons would be fair game. This is clear because we are implementing the operation the goal of which is to remove any threat to the Russian Federation coming from the Ukrainian soil," Lavrov said in an English-language interview with the RT television channel.

The Kremlin says Russian President Vladimir Putin in a phone call with Germany’s leader Olaf Scholz accused Ukraine of “seeking to drag out” negotiations with Russia to end the war by putting forward “new unrealistic proposals."

Putin told Scholz Russia was “nonetheless ready to continue the search for a solution within the bounds of its well-known principled approaches,” the Kremlin said in a readout of the call.

It’s a negative sign for the ongoing talks with Ukraine that both sides have suggested have made some progress this week.

-ABC News' Patrick Reevell

Russian missiles have hit the western Ukrainian city of Lviv for the first time Friday, a key location that had been spared from the assault until now.

The missiles struck the area around the city's airport, according to the mayor, Andriy Sadovyi, around 6:30 a.m. local time, hitting an aircraft repair facility and destroying the building.

There were no immediate reports of casualties in the attack, according to the mayor.

Preliminary data indicated that six cruise missiles were fired from the Black Sea, according to the country's western military command. Two were destroyed by anti-aircraft missile systems.

-ABC News' Martha Raddatz

The Biden administration is "focused" on ways to help Ukrainian refugees, as the number of people displaced by the war continues to grow, according to U.S. officials.

More than 3 million people have fled Ukraine since Russia's invasion began, according to the United Nations' refugee agency, in Europe's largest refugee crisis since World War II.

"As the numbers increase, as the burden increases for European partners, we will certainly do everything we can to help," Secretary of State Antony Blinken told reporters Thursday, adding it was "something we're very focused on right now."

Without offering specifics, Blinken confirmed the administration is "looking at things that we can do ourselves and do directly -- for example, looking at steps we may be able to take on family reunification and other things."

One limited option is fast-tracking the process to admit refugees to the U.S. itself, which is defined by law and requires a referral from the U.N.'s refugee agency and thorough vetting. A senior administration official told ABC News that the refugee program "is not an emergency response program, so our goal would be to provide humanitarian assistance to keep people safe where they are for now."

As Blinken told reporters, the referral process to be granted refugee status "takes time." Refugee resettlement is a yearslong process, and there are already 7,000 Ukrainian refugees in the pipeline, according to resettlement agency Church World Service.

The senior administration official also said U.S. embassies and consulates in the region are processing emergency visa applications, but that they are overwhelmed. "We are not able to process the volume of the people who are thinking about that as an option," the official said.

Refugee resettlement agencies say the administration is considering using the Lautenberg program, which allows religious minorities -- including Ukrainian Greek Catholics and Ukrainian Autocephalous Orthodox Christians -- to bring family members to the U.S. with a potentially expedited refugee status. One agency told ABC News there are thousands of Ukrainian applicants who the U.S. could swiftly admit.

The administration has already approved temporary protected status for any Ukrainians in the U.S. before March 1 -- allowing them to stay and work in the U.S. for at least the next 18 months.

-ABC News' Ben Gittleson, Sarah Kolinovsky and Conor Finnegan

All Russian troops have left the Ukrainian cities of Kyiv and Chernihiv, withdrawing north toward the borders of Belarus and Russia to consolidate before likely redeploying to the Donbas region in eastern Ukraine, a senior U.S. defense official told reporters Wednesday.

But even with the Russians gone, the territory remains treacherous.

"There are some indications that they left behind mines and things like that, so the Ukrainians are being somewhat careful in some areas north of Kyiv as they begin to clear the ground and clear the territory and re-occupy it," the official said.

While the U.S. hasn't yet seen these troops redeploy elsewhere in Ukraine, it'll likely happen soon, according to the official. Ukrainian forces are preparing for a major fight in Donbas, the official said.

The official also said the Pentagon is "monitoring" an apparent nitric acid explosion in Ukraine's Luhansk region, which Russia blamed on Ukraine.

"We've seen the Russians claim that this was a Ukrainian attack on this. We do not believe that is true," the official said. "We do believe that the Russians are responsible, but exactly what they used when they did it, why they did it, what the damage is, we just don't have that level of detail," the official said.

The official also noted that a small number of Ukrainians currently in the U.S. for "professional military education" were pulled aside for a couple days of training on Switchblade drones, which the U.S. is sending overseas as part of its military aid, according to the official.

"Although it's not a very difficult system to operate, we took advantage of having them in the country to give them some rudimentary training on that," the official said.

-ABC News' Matt Seyler