Russian Foreign Minister Sergey Lavrov "diverted" U.S. Secretary of State Antony Blinken's calls to reconsider the decision to suspend Russia's participation in the New START treaty, Russia's foreign ministry told Interfax, Russian news agency.

“If they want to return to diplomacy, let them return. If they are engaged in self-promotion and such inexpensive PR, well, this is possible. True, the result will be appropriate," Maria Zakharova, a spokesperson for the ministry, told Russian TV channel Rossiya-1.

-ABC News' Natalia Shumskaia

U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov had an "on the go" talk during the G-20 Meeting of Foreign Ministers in India, but there were no negotiations, Russian Foreign Ministry spokeswoman Maria Zakharova told TASS, a Russian news agency, Thursday.

"Blinken asked for a contact with Lavrov. Sergey Viktorovich [Lavrov] had communication on the go during the second session. But there were no negotiations, no meeting or so on," the diplomat said.

Blinken had said earlier in the day during a press conference he had "spoke briefly" with Lavrov and discussed ending the war, as well as Russia rejoining the New START Treaty on nuclear arms.

"I told the foreign minister what I and so many others said last week at the United Nations and what so many G-20 foreign ministers said today: End this war of aggression, engage in meaningful diplomacy that could produce a just and durable peace," he said. "The United States stands ready to support Ukraine through diplomacy to end the war on this basis."

A senior State Department official downplayed any hopes that the conversation moved the needle on any of the topics.

-ABC News' Tanya Stukalova and Shannon Crawford

Ukraine has shot down 80% of Russian missiles, according to Commander of the Joint Forces of the Ukrainian Air Force Serhiy Nayev.

Nayev made the assessment in a Facebook post on Wednesday about the effectiveness of the air defense system.

"The enemy is also changing his tactics and ways of using air strike means, so we test after every hit," he wrote. "This analysis proves that commanders, respectively, make decisions that ensure the durability of the air defense is at the highest level."

-ABC News' Ellie Kaufman

Colonel-General Oleksandr Syrsky, the commander of Ukraine's Eastern Group of Forces, will send additional units to Bahkmut, according to Ukraine's Deputy Defense Minister Hanna Malyar.

"Bakhmut has been the epicenter of hostilities for several months now. The enemy has concentrated its key efforts there because it aims to reach the borders of the Donetsk region. The situation there is really tense and difficult," Malyar said.

Ukrainian President Volodymyr Zelenskyy echoed that statement in his nightly address.

"The most difficult situation is still Bakhmut and the battles that are important for the defense of the city," he said.

-ABC News' Ellie Kaufman and Will Gretsky

A Moscow court has sentenced one of Russia's best-known opposition leaders, whose family live in the U.S., to 25 years in prison in what is widely seen a show trial.

Vladimir Kara-Murza is the most high-profile opponent of Russian President Vladimir Putin to be jailed since Alexey Navalny.

Kara-Murza's extraordinarily harsh sentence is one of the lengthiest any opposition figure has received under Putin and illustrates how repressive Russia has become during the war in Ukraine, reverting to something much closer to the USSR where no opposition is tolerated.

Kara-Murza was convicted of treason, as well as "discrediting Russia's armed forces," a new law that effectively criminalizes criticizing the war in Ukraine. He was also convicted of belonging to a banned organization. The charges are widely seen as politically motivated.

Kara-Murza is one of Russia's best-known pro-democracy figures and a veteran critic of Putin.

Kara-Murza, who holds both British and Russian citizenship, spent many years living in the United States and his wife and children still live in Virginia. He was close to the late U.S. Sen. John McCain, who championed human rights in the former Soviet Union.

Dozens of journalists and Western diplomats attended the court hearing on Monday, including the U.S. ambassador who read out a statement condemning the sentence.

"We support Mr. Kara-Murza and every Russian citizen to have a voice in the direction of their country. Mr. Kara-Murza and countless other Russians believe in and hope for a Russia where fundamental freedoms will be upheld. And we will continue to share those hopes and work for that outcome," Amb. Lynne Tracy said.

Kara-Murza previously has survived being poisoned not once but twice. In 2015 and then again in 2017, he suffered organ failure after being exposed to an unknown toxin. Independent researchers later linked the poisoning to the same team of FSB poisoners who targeted Navalny.

He chose to return to Russia after the war began, believing it was important to continue to campaign for freedom in his country and has been an outspoken critic of the invasion.

His trial was held entirely behind closed doors, but a letter containing his closing statement to the court has been released to reporters.

"I only blame myself for one thing," Kara-Murza said in the statement. "I failed to convince enough of my compatriots and politicians in democratic countries of the danger that the current Kremlin regime poses for Russia and for the world."

"Criminals are supposed to repent of what they have done. I, on the other hand, am in prison for my political views. I also know that the day will come when the darkness over our country will dissipate.

-ABC News' Patrick Reevell