In his latest national address, Ukrainian President Volodymyr Zelenskyy urged Ukrainians to stay vigilant and warned that Russia still has "significant potential" to continue its attacks.

The comments come after Russia claimed it would move forces away from Kyiv and Chernihiv and the latest round of in-person peace negotiations kicked off in Turkey.

Zelenskyy said there were positive signals that came out of Tuesday's talks in Istanbul and that Ukraine is willing to continue the negotiation process, but that his country's sovereignty and territorial integrity must be guaranteed.

"There can be no compromise on sovereignty and our territorial integrity. And there will not be any," he said.

The president called for sanctions targeting Russia to be intensified amid continued shelling.

"The question of [lifting Russian] sanctions cannot even be raised until the war is over, until we get back what's ours and until we restore justice," he said.

-ABC News' Fidel Pavlenko

Ukraine outlined proposals for a new system of security guarantees for their country during talks with Russia in Turkey on Tuesday, officials said.

Ukraine is seeking security guarantees comparable to NATO's collective defense clause, Article 5, in that in the event of an attack on Ukraine, "guarantor countries" would be legally obligated to provide arms and impose a "no-fly" zone over Ukraine, according to David Arakhamia, the head of Ukraine's negotiation team. The security guarantees would "not work temporarily" in the currently occupied territories of the Donetsk and Luhansk regions and Crimea, the government said.

The suggested list of guarantors includes permanent members of the UN Security Council -- the U.S., Great Britain, France, China and Russia -- as well as Turkey, Germany, Canada, Italy, Poland and Israel.

In exchange, Ukraine's would "undertake not to deploy foreign military bases, foreign military contingents on its territory, not to join military-political alliances, and military exercises on the territory of Ukraine will be possible with the consent of the guarantor countries," the government said.

It is "fundamentally important" that a potential treaty does not deny Ukraine's right to join the European Union, Oleksandr Chalyi, a member of the Ukrainian delegation, said in a statement.

Negotiations with Russia will continue in the next two weeks, and Ukraine has already begun consultations with all countries they would like to see on the guarantor list, according to Chalyi.

-ABC News' Christine Theodorou

The U.S. is seeing some movement of Russian troops away from Kyiv, as Russia has suggested, but the White House does not view this as a withdrawal but rather a "redeployment," a White House official told ABC News.

"We're seeing some movement of troops away from Kyiv, which could be an indication of [Russian President Vladimir] Putin having to adjust his original plan," a White House official said. "But no one should read too much into an adjustment -- should momentum build, Russia could change its plans again at any moment, or this could just be a regroup."

"No one should be fooled by Russia’s announcements. We believe any movement of forces from around Kyiv is a redeployment, not a withdrawal, and the world should be prepared for a major offensive against other areas of Ukraine," the official added.

During a Pentagon briefing Tuesday, top spokesman John Kirby confirmed that a "small number" of Russian troops are repositioning away from Kyiv, but he’s not calling it a withdrawal as the Russians have characterized it.

Kirby told reporters the U.S. is not convinced that the threat to Kyiv is over, but that it could mean that Russia is preparing to move troops north of Kyiv for another assault elsewhere in Ukraine.

"Where exactly we don't know," he said. "I would just note that the Russians themselves have said in the same breath they're saying they're withdrawing that they're that they're reprioritizing the Donbas area, eastern Ukraine."

-ABC News' Molly Nagle and Luis Martinez

President Biden on Tuesday expressed skepticism regarding Russia’s claim that its forces will move away from Kyiv and Chernihiv.

"I don't read anything into it until I see what their actions are. We’ll see if they follow through on what they’re suggesting," Biden said during a joint press conference with Singapore's prime minister.

Biden also commented on the ongoing negotiations in Turkey between Ukraine and Russia and said there is consensus among Western allies to "see what they have to offer."

"But in the meantime, we’re going to continue to keep strong sanctions. We are going to continue to provide the Ukrainian military with their capacity to defend themselves and we are going to continue to keep a close eye on what's going on," Biden said.

-ABC News' Justin Gomez

About 631 residents of the bombed-out city of Mariupol in southeast Ukraine were able to evacuate on Thursday, according to a Ukrainian official.

Ukrainian Deputy Prime Minister Iryna Vereshchuk said the residents fled the city in private vehicles after 45 buses reserved to drive them out failed to make it into the city. Vereshchuk said another 600 civilians still in Mariupol plan to try to evacuate again on Friday.

Ukrainian President Volodymyr Zelenskyy said Thursday in an address to lawmakers of Australia, the Netherlands and Belgium that more than 90% of all buildings in Mariupol have been completely destroyed by Russian strikes.

"Thousands of peaceful Mariupol residents died, people are buried just in the city, in the courtyards of high-rise buildings, or rather, what is left of the high-rise buildings," Zelenskyy said.

-ABC News' Christine Theodorou