Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty in speech denouncing West

Moscow is closely "following" the midterm elections in the United States and knows that some Republican candidates have proposed to cut the country's military aid to Ukraine, according to Russian Deputy Foreign Minister Alexander Grushko.

"Naturally, we are following the developments in the United States," Grushko said in an interview with Russian state-owned television network Zvezda on Tuesday. "We are aware that a number of prominent Republicans favor reducing the military assistance to Ukraine, because they proceed from the position that what Democrats are currently doing is irrational."

If Republicans are triumphant, Grushko said, the U.S. Congress could ramp up pressure on European nations regarding their defense budgets.

"We remember that one of [former U.S. President Donald] Trump's key slogans when he came to power was that the Europeans should pay for their defense themselves," he added. "Largely thanks to his efforts, European countries took enhanced commitments to increase their defense budgets to 2%. And there have been talks that defense spending should now reach at least 3%. The United States will continue to pursue the policy it has been running since 1949."

Ukrainian President Volodymyr Zelenskyy raised the notion of holding "genuine peace talks" in his daily address to his nation on Tuesday.

Zelenskyy set out conditions for peace talks with the Russians, requiring the restoration of territorial integrity, compensation for all damages caused to his country, punishment of every war criminal and guarantees that another Russian invasion will not happen again.

"These are completely understandable conditions," Zelenskyy said.

He said that earlier Tuesday he gave a virtual speech to the United Nations Climate Change Conference in Egypt, telling dozens of world leaders of the ongoing Russian aggression.

"Anyone who is serious about the climate agenda should also be serious about the need to immediately stop Russian aggression, restore our territorial integrity and force Russia into genuine peace negotiations," Zelenskyy said.

He added that previous proposals from Ukraine for peace talks have prompted "insane Russian responses with new terrorist attacks, shelling or blackmail."

U.S. ambassador to the United Nations Linda Thomas-Greenfield met with Ukrainian President Volodymyr Zelenskyy and members of his leadership team in Kyiv on Tuesday "to discuss the unwavering U.S. commitment to the sovereignty and territorial integrity of Ukraine," according to a statement from U.S. Mission to the U.N. spokesperson Nate Evans.

"She reiterated that the United States is steadfast in its support for Ukraine and is prepared to stand with Ukraine as long as it takes," Evans said.

"Ambassador Thomas-Greenfield and President Zelenskyy discussed international efforts to minimize the impact of Russia’s aggression on global food security, including through sustaining and expanding the UN-brokered Black Sea Grain Initiative, and to ensure accountability for war crimes and atrocities perpetrated on the Ukrainian people," he added. "She committed to continuing to work at the United Nations to strengthen international support for Ukraine's sovereignty and to urge Member States to defend international law and the Charter of the United Nations."

ABC News has obtained a letter sent by a top Ukrainian official to senior members of Congress, asking them to assist Ukraine's calls for additional air defense systems to counter the attack drones built and supplied by Iran to bolster Russia's war effort.

Russia has launched waves of deadly attacks in recent weeks, using Iranian-made drones that explode on impact to strike power plants, killing civilians and causing rolling blackouts, plunging millions of Ukrainian homes into darkness.

In the letter, the chairman of the Ukrainian parliament, Ruslan Stefanchuk, calls on the U.S. to provide Ukraine with highly mobile air defense systems known as C-RAMs, saying they would help protect "important objects, especially crucial power plants."

-ABC News' Tom Soufi Burridge, Luis Martinez and Natalya Kushnir