Russia-Ukraine updates: Russian missiles hit close to nuclear reactors: IAEA director

Ukraine has amassed a million-strong fighting force equipped with western weapons to recover its southern territory from Russia, Ukrainian Defense Minister Oleksii Reznikov said in an interview with The Sunday Times.

According to Reznikov, Ukrainian President Volodymyr Zelenskyy had ordered Ukraine’s military to retake occupied coastal areas which are vital to the country’s economy.

Reznikov said on Friday that “more than a million defenders protect Ukraine.” The majority of these forces -- around 700,000 troops -- is made up of Ukrainian soldiers, Reznikov said at an online conference.

The remaining units consist of policemen, border guards and members of the National Guard, the official added. Reznikov also said that Ukraine has turned into a certain kind of training ground where new types of weapons and innovative solutions are being used.

Ukraine has “passed the test” with its successful use of recently delivered American long-range artillery systems, Reznikov told The Wall Street Journal .

But as the war shifts primarily to an artillery battle, the defense minister added, more longer-range weapons will be needed to recapture lost Ukrainian territory.

“We need to refresh our platoons, change them and make replacements because we also have a lot of losses,” Reznikov said. “We are waiting for more armor, more weaponry from our partners.”

Russia recruits prisoners with combat experience

Russian forces are recruiting prisoners with combat experience to fight in Ukraine, a local prisoner's rights group said on Monday.

The Moscow-linked Wagner private military contractor and Russia’s Federal Security Service were reportedly offering convicts work in occupied Ukrainian territories.

Recruitment campaigns were run at penal colonies in several Russian cities, including St. Petersburg and Rostov, the group said. Several hundred prisoners had allegedly agreed to join Russian forces in Ukraine, the rights group said. The group said it obtained the information from relatives and prisoners who had reached out to the NGO themselves via its hotline.

The group's report appeared to corroborate independent media investigations detailing Wagner recruiters offering high salaries and compensation to their families in case of their deaths.

-ABC News' Edward Szekeres, Yulia Drozd, Fidel Pavlenko and Max Uzol

Russian strikes targeted several Ukrainian cities, including Kharkiv, Mykolaiv and Odesa, on Sunday night and Monday morning.

A strike in Kharkiv on Sunday night hit a residential building downtown, a school and a warehouse. The emergency service said it rescued a woman from beneath the debris.

Another attack that hit the city late in the morning left at least three people dead and 31 wounded, including two children, officials said.

At least six missiles hit Mykolaiv on Monday morning, local authorities said, injuring three people.

A missile strike also targeted Odesa on Monday morning, local officials said. Russian jets in Crimea fired four missiles at the city, with one missile striking a residential building. The number of casualties was unknown.

-ABC News' Edward Szekeres, Yulia Drozd, Fidel Pavlenko and Max Uzol

It is vital that Ukraine retakes territory in the south of the country before winter sets in, according to an adviser to President Volodymyr Zelenskyy.

Serhiy Leshchenko told ABC News that any military offensive would be much harder during the winter.

The Ukrainian government fears that Russia could use a deadlock during the winter to consolidate its control over newly occupied territories in the Kherson and Zhaporizhia regions, he said, and it's therefore crucial for Ukraine to counterattack effectively during the coming months.

"Our concern is that if winter comes, under Russian occupation of these territories, Russia will use this three, four months of the winter for fast integration of these territories into Russia," Leshchenko said, "and that is why it is very important to have counterattack in the south before winter starts to take them out from this territory before winter starts."

The presidential adviser also renewed calls for the United States to provide more High Mobility Artillery Rocket Systems or HIMARS.

On Friday, the Biden Administration announced it would provide four more HIMARS to Ukraine on top of the eight that had already been delivered.

Leshchenko said Ukraine was grateful for the 12 HIMARS but that it was nowhere near enough.

"You provided good weapons, but... it's not enough," he said. "Twelve HIMARS is better than nothing, but it’s better that we have not 12, but 112."

"It would change the situation on the front line dramatically and very fast," he added.

-ABC News' Tom Burridge

At least six survivors have been rescued Sunday from the rubble of three apartment buildings purportedly hit by Russian missiles in the Donetsk region of eastern Ukraine, but emergency officials said at least 24 people, including a 9-year-old child, remain unaccounted for and are feared buried under the debris.

At least 15 people were killed when four Russian rockets slammed into the residential buildings Saturday evening in the town of Chasiv Yar, according to Viacheslav Boitsov, deputy chief of emergency service in the Donetsk region.

"They were likely Iskander missiles. A part of a building collapsed, from the fifth to the first floor. There are likely injured people still (under the rubble)," Boitsov told The Associated Press.

Pavlo Kyrylenko, governor of the Donetsk region that includes Chasiv Yar, told The AP that as many as 24 people were believed still trapped in the rubble, including a 9-year-old child.

Russian officials claimed its forces struck Ukrainian army hangars storing U.S.-produced M777 howitzers, a type of artillery, near Kostyantynivka in Donetsk region, but, so far, it has not claimed responsibility for the missile strike on the residential building in Chasiv Yar.

The latest rescue came late Sunday when emergency workers rescued a man after a lengthy operation to free him from under the concrete. Video showed a rescue team carrying the man out of the ruins on a stretcher. He was whisked away to a hospital. It was not immediately clear how severely injured he was.

Emergency Services officials said the latest rescue brought to six the number of survivors dug out of the rubble.

Cranes and excavators worked alongside rescue teams into the night to clear away the ruins of one building, its walls wholly shorn off by the impact of the strike.