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

Russia’s Wagner mercenary group said it will retreat from Bakhmut because of severe shortages in ammunition, according to Yevgeny Prigozhin, the group's leader. He said his forces would withdraw on May 10, blaming Russia’s defense ministry for the retreat.

Wagner has played a crucial role for months in the fighting for Bakhmut, sustaining huge casualties. The announcement and the suggestion of bitter infighting within Russia’s military forces signals division and disorganization just as Russia is bracing for a major Ukrainian counteroffensive.

Prigozhin said he was taking the decision in retaliation against Russia’s military leadership, which he accused of deliberately starving his troops of ammunition because they are jealous of Wagner’s success.

Prigozhin and Russia’s defense ministry have been in a one-sided public feud for months. Prigozhin claims it's now reached a breaking point, delivering a blistering attack on Russia's senior military command in the video announcing the withdrawal. He accused them of being "cowards" and of denying Russians a victory in Bakhmut because of their "petty envy."

Ukrainian military officials said they did not believe Wagner forces would retreat from Bakhmut, suggesting they believed his announcement was an attempt to excuse his failure to seize the city by May 9 as he pledged. A spokesman for Ukraine's eastern command, Sergiy Cherevatyi, said Wagner was running out of fighters, not ammunition.

-ABC News' Patrick Reevell