Russian Deputy Foreign Minister Sergey Ryabkov told ABC News during an exclusive interview in Moscow on Monday that he believes the warring parties are close to a deal.

The U.S. has agreed to provide unspecified security guarantees to Ukraine as part of a peace deal to end Russia's nearly four-year war, and more talks are likely this weekend, U.S. officials said Monday following the latest discussions with Ukrainian President Volodymyr Zelenskyy in Berlin.

The Kremlin has described Ukraine’s push to join NATO as one of the “root causes” of the conflict. Russia sees an expanding NATO as a major security threat. But NATO’s expansion into the Baltics and other post-Soviet states is driven by a fear that Moscow would one day invade and try to fold them back under its control—as seen in Ukraine.

Ukrainian President Volodymyr Zelenskyy said in a social media post on Sunday morning that "hundreds of thousands" of Ukrainians were without electricity across multiple regions following Russian missile and drone attacks on the country's energy infrastructure.

The United States, Ukraine and major European countries have reached consensus on 90 percent of terms for a deal to end Ukraine’s war with Russia, two senior U.S. officials said Monday, but

Ukraine has used long-range drones to attack Russian oil platforms as it expands its strikes on the country's energy sector.

The European Union is set to lock up Russia’s assets in Europe until Russia ends its war on Ukraine and compensates for the damage.