Ukrainian forces have killed 225 Russian fighters and injured another 306 in the past 24 hours in the Bakhmut area, according to Serhiy Cherevaty, the spokesman for the Eastern Group of Forces of the Ukraine army.

Russia and Ukraine have been locked in a brutal battle for the city in eastern Ukraine for months, with both sides seeing high rates of casualties.

Cherevaty said that in the last day, the occupiers in the area of Bakhmut and nearby villages -- including Orikhovo-Vasylivka, Bohdanivka and Ivanivskoho -- tried to attack Ukrainian positions 42 times. There were 24 combat clashes in the Bakhmut area alone.

In total, in the Bakhmut direction, the occupiers shelled Ukrainian positions 256 times with various types of artillery and multiple launch rocket systems, Cherevaty said. Of them, 53 shellings were in the area of Bakhmut itself.

-ABC News' Will Gretsky

Russia is working to increase its weapons production amid an "urgent" need, President Vladimir Putin said Wednesday.

"Prosecutors should supervise the modernization of defense industry enterprises, including building up capacities for the production of an additional volume of weapons. A lot of effort is underway here," Putin said at a meeting of the Collegium of the Prosecutor General's Office of the Russian Federation.

Putin added that the weapons, equipment and ammunition are "urgently" needed.

-ABC News' Will Gretsky

Poland may send Ukraine MiG-29 fighter jets in the next four to six weeks, Prime Minister Mateusz Morawiecki said on Tuesday, according to Reuters.

Poland has previously said it would consider sending the Soviet-designed fighter jets to Ukraine.

When asked during a press briefing Tuesday how long it could take to supply the aircraft, Morawiecki said, "That could happen in the coming 4 to 6 weeks," according to Reuters.

The White House is welcoming reports that Chinese President Xi Jinping plans to soon speak with Ukrainian President Volodymyr Zelenskyy for the first time since Russia’s invasion began, while cautioning that after speaking with Ukrainian counterparts, "they have not yet actually gotten any confirmation that there will be a telephone call or a video conference."

"We hope there will be," national security adviser Jake Sullivan said during a briefing on Air Force One. "That would be a good thing because it would potentially bring more balance and perspective to the way that the new PRC is approaching this, and we hope it will continue to dissuade them from choosing to provide lethal assistance to Russia."

"We have been encouraging President Xi to reach out to President Zelenskyy because we believe that PRC and President Xi himself should hear directly the Ukrainian perspective and not just the Russian perspective on this," Sullivan continued. "So, we have in fact, advocated to Beijing that that connection take place. We've done so publicly and we've done so privately to the PRC."

Sullivan said the U.S. has “not yet seen the transfer of lethal assistance of weapons from China to Russia," after previously warning it was being considered.

"It's something that we're vigilant about and continuing to watch carefully," he added.

-ABC News' Justin Gomez

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