Ukrainian President Volodymyr Zelenskyy on Friday blasted Russia over the discovery of more than 400 bodies at a mass grave in an area recaptured by Ukraine's military.

"Russia leaves only death and suffering," he wrote on social media, along with the words: "Murderers. Torturers."

In a separate interview, Zelenskyy told Reuters news agency there was some evidence of torture and war crimes at the burial site near the northeastern city of Izium.

In his nightly video address, Zelenskyy compared the alleged atrocities in Izium with those committed in the town of Bucha on the outskirts of Kyiv in spring. He also reiterated Kyiv's demand that an international tribunal be set up for war crimes in Ukraine and called Russia a "terrorist state."

"There is already clear evidence of torture, humiliating treatment of people. Moreover, there is evidence that Russian soldiers, whose positions were not far from this place, shot at the buried just for fun," Zelenskyy said.

Regional governor Oleg Synegubov said that 99% of the bodies exhumed Friday had signs of violent death.

"There's likely more than 1,000 Ukrainian citizens tortured and killed in liberated territories of Kharkiv region," he wrote on social media.

Another Ukrainian official said they had found 10 alleged "torture centers" in the wider Kharkiv region that was recaptured from Russian invaders.

"Coming to Balakliya or Izium, we see a huge number of crimes committed against the civilian population," police chief Ihor Klymenko said in a statement.

In the town of Balakliya, up to 40 people were reportedly detained, humiliated and tortured at the local police station.

"There was torture, we saw traces of bare electric wires on people's hands through which electricity was sent during interrogations," Klymenko said. 

Six other torture sites were found in Izium, but had been completely destroyed, he added.

The UN High Commissioner for Human Rights office said it plans to send a team to verify the claims.

White House national security spokesman John Kirby described the reports as "horrifying."

EU foreign policy chief Josep Borrell said the bloc was "deeply shocked" at the discovery of mass graves, adding, "We condemn these atrocities in the strongest possible terms."

French President Emmanuel Macron condemned what he described as "atrocities" committed in Izium.

"I condemn in the strongest terms the atrocities committed in Izyum, Ukraine, under Russian occupation," Macron tweeted.

France's president said that those responsible "will have to answer for their acts. There is no peace without justice."

Here's a roundup of some of the other key developments regarding Russia's invasion of Ukraine on September 16.

Moscow can't achieve initial war aims — Pentagon intelligence chief

Pentagon intelligence chief Scott Berrier said that Moscow is incapable of achieving its war aims, amid news of Ukrainian forces recapturing territory.

"We're coming to a point right now where I think Putin is going to have to revise what his objectives are for this operation," Berrier said. "It's pretty clear right now that he's ... not going to be able to do what he initially intended to do.''

"The Russians planned for an occupation, not necessarily an invasion, and that has set them back," he argued.

Putin: Russia 'not in a hurry' to end war

Russian President Vladimir Putin said there were no plans to adjust Russia's military operations in Ukraine despite a counteroffensive by Kyiv's forces.

"We are not in a hurry... there are no changes," he told reporters during a regional summit in Uzbekistan. 

"Our offensive operations in Donbas itself do not stop. They are going at a slow pace... the Russian army is occupying newer and newer territories." Putin added.

The Russian leader said his forces were "not fighting with a full army" but only contract soldiers, and said the main goal remained "the liberation of the entire territory of Donbas."

"We are really quite restrained in our response to this, for the time being," Putin said of the recent Ukrainian success in recapturing large areas in the northeast and south. "If the situation continues to develop in this way, the response will be more serious."

Earlier, Putin told Indian Prime Minister Narendra Modi that he shared New Delhi's concern about the conflict and hoped the fighting would end "as soon as possible."

US pledges new military aid for Ukraine

The United States has announced further military aid worth $600 million for Ukraine. The package includes rocket launchers that have recently played an important role in helping Kyiv's forces secure wins against the Russian army. 

The aid is supposed to help keep the offensive going and to "boost momentum," the White House said.

US Secretary of State Antony Blinken said in a statement that the aid was "carefully calibrated to make the most difference on the battlefield and strengthen Ukraine's hand at the negotiating table when the time is right.'' 

He praised the ''admirable grit and determination'' of Ukrainian soldiers "defending their homeland and fighting for their future.''

Since Russia's invasion of Ukraine in February, the US has sent military aid worth over $15 billion to Ukraine. The Defense Department has delivered weapons and ammunition on more than 20 occasions. 

Berlin: Moscow's defense reserves likely smaller than assumed

German Defense Minister Christine Lambrecht said that Moscow's military reserve could be smaller than initially assumed after suffering significant troop and equipment losses in Ukraine amid the impact of Kyiv's latest counter-offensive. 

"Russia's military has suffered significant losses by now — both in troops and equipment,"  Lambrecht said in an interview published Friday.

Berlin, Athens seal military vehicle swap to aid Ukraine

Germany and Greece have agreed on a swap deal to deliver 40 BMP-1 tanks to Ukraine, the German Defence Ministry has said.

Under the plan, Greece will supply Kyiv with 40 Soviet-designed BMP-1 infantry fighting vehicles, while Athens will receive 40 Marder infantry fighting vehicles from Germany from industrial stocks.

Implementation will begin immediately, the ministry added.

The idea for an exchange of military vehicles arose shortly after Russia invaded Ukraine on February 24.

The plan allows the Ukrainian armed forces to be supplied with Soviet-era systems which they are used to operating. This eradicates the need for extensive training.

Those countries that give up their Soviet-era weapons are supplied with modern Western equivalents.

Kyiv blasts Berlin over failure to send tanks

Ukraine's foreign minister has renewed criticism of Germany for failing to send tanks to help his country fight back against Russia's aggression.

"We ask for Leopard tanks and Marder (armored vehicles), and Germany supplies armored vehicles of the Dingo type," he said in an interview with the Frankfurter Allgemeine Zeitung on Friday.

He said the new weapons pledged by Berlin were "not what we need most."

"I get the impression there is a kind of weapon wall in Berlin I think the time is ripe for the chancellor to tear down this wall." 

Germany has sent a raft of different armaments to Ukraine but has so far refused to transfer Leopards and Marders, despite repeated requests from Kyiv.

Berlin argues it will not "go it alone" on weapons deliveries, despite mounting pressure at home and abroad. It points out that no other ally has transferred Western-made battle tanks to Ukraine.

A German government source reiterated the position on Thursday "for the foreseeable future."

Kremlin in 'certain amount of disarray,' Russia expert tells DW

Military aid from the United States has helped Ukraine to make recent advances against Russian troops, a security analyst told DW on Friday.

"The Kremlin is in a certain amount of disarray and confusion and, perhaps, in shock" over the Ukrainian fightback, Jenny Mathers, an expert in Russian politics and security and a senior lecturer at Aberystwyth University in Wales, said.

"They certainly didn't expect this dramatic counteroffensive [to result] in a humiliating defeat by their own forces."

She said that war has not gone the way that Putin wanted and the disarray likely had an impact on how Putin was perceived by ordinary Russians.

"So much of Putin's strength comes from reputation ... from other people's responses to him. And once there's evidence that that strength is not quite what we thought it was, then the whole edifice begins to crumble and is certainly very vulnerable," Mathers told DW.

Stoltenberg: 'Not the beginning of the end of the war'

NATO Secretary General Jens Stoltenberg has warned against expectations of the war ending soon despite Ukraine's recent military successes against Russia. 

"It is of course extremely encouraging to see that Ukrainian forces have been able to retake territory and also strike behind Russian lines," Stoltenberg told Britain's national broadcaster BBC. 

"At the same time, we have to understand that this is not the beginning of the end of the war. We have to be prepared for this to drag on for a long time."

Zelenskyy cleared to address UN General Assembly virtually

Ukrainian President Volodymyr Zelenskyy will be allowed to address next week's United Nations General Assembly via video link, a majority of member states have agreed. 

Of the UN's members, 101 approved a motion to this effect and seven countries voted against. There were 19 abstentions. 

Belarus failed with an amendment to the motion that would have allowed a video message for all UN countries.

Speaking at the General Assembly via video link gives Zelensky a big political stage, especially since Russian President Vladimir Putin will not be present at the event.

Foreign Minister Sergei Lavrov will attend in his place.

More on the war in Ukraine

Builders in Kyiv are working non-stop to repair homes damaged by Russian shelling. Residents hope to move back in before the temperatures drop. Read DW's report on how reconstruction is booming in Kyiv.

In a new blueprint for a postwar order, several countries are to guarantee Ukraine's security as a precursor to NATO membership. Russia has expressed its disapproval in no uncertain terms. DW looked at Ukraine's push for security guarantees in new world order. 

los/rt,kb (AFP, AP, Reuters, dpa)