There was an eerie quietness across Kyiv on Friday afternoon, as Russian forces closed in on the Ukrainian capital.

A senior U.S. official told ABC News that he believes the pause around Kyiv was due to the Russian military reinforcing troops and resupplying ammunition and food, and that Russia still wants a stranglehold on the city over the next 24 to 48 hours.

The official also expressed great concern about civilian causalities if Russian forces do move in. While there appeared to be a renewed effort at diplomacy on Friday, the United States believes any noise Russia makes about negotiations is simply stalling, the official said.

-ABC News' Martha Raddatz

Russia claimed Friday that Ukrainian President Volodymyr Zelenskyy has agreed to discuss neutrality for his country.

"Zelenskyy stated his readiness to discuss the neutral status of Ukraine," Kremlin spokesman Dmitry Peskov told reporters during a daily call. "From the beginning, Russia's President Vladimir Putin spoke about how the goal of the operation to the [separatist regions], including a path to the demilitarisation and de-Nazification of Ukraine. But that is actually also an essential component of neutral status."

Peskov added that Putin is prepared to send a delegation to neighboring Belarus to hold talks with Ukrainian officials in Minsk.

If the Kremlin's claims are true, it would amount to Zelenskyy surrendering to Russia's demand that Ukraine pledges to never join NATO.

Earlier Friday, Zelenskyy called on Putin to hold talks "to stop people dying." But he did not mention neutral status.

The comments came as Russian troops reached the center of Ukraine's capital, Kyiv, and engaged in fighting with Ukrainian troops.

-ABC News' Patrick Reevell

Russia claimed on Friday afternoon that its forces have blocked Kyiv from the west, which would begin a partial encirclement of the Ukrainian capital.

According to a statement from the Russian Ministry of Defense, Russian forces also have completely blocked the northern Ukrainian city of Chernihiv, about 90 miles north of Kyiv, and now have full control of a key Ukrainian military airport in Hostomel, a town on the edge of the capital. Some 200 Russian helicopters were allegedly used in the attack on the airport.

While ABC News could not independently verify Russia's claims, the Ukrainian military has acknowledged that it does not have full control of the airport in Hostomel.

The Russian Ministry of Defense alleged that Russian forces are "doing everything possible to prevent civilian casualties" and "will not deliver any strikes on residential areas of Kyiv." However, fighting is already taking place in residential areas and Ukrainian authorities said homes have been bombed in and around Kyiv.

-ABC News' Anastasia Bagaeva and Patrick Reevell

Ukrainian President Volodymyr Zelenskyy called on Russian President Vladimir Putin to hold negotiations and cease the deadly attacks on his country.

"Fighting is ongoing all over Ukraine. Let's sit at the table for negotiations to stop people dying," Zelenskyy said in a televised address Friday afternoon.

But he did not order Ukrainian troops to stop defending their country, instead telling them: "Stand tough. You're everything we have. You're everything that is defending us."

Zelenskyy criticized Europe's response to the Russian invasion of Ukraine, calling it too slow and noting divisions. He also issued a dire warning to the rest of Europe.

"It's not just Russian invasion in Ukraine, it's the beginning of the war against all Europe, against its unity, all human rights, against all the rules of coexistence on the continent, against European countries' refusal to change the borders by force," he said.

-ABC News' Julia Drozd and Patrick Reevell