Russia is getting ready to go on the offensive again in the Moscow-controlled eastern part of Ukraine, said Colonel-General Oleksandr Syrskyi, commander of the Ukrainian military’s ground forces.

“After a month of fierce fighting and significant losses in the Kupiansk and Lyman directions, the enemy is regrouping its forces and means, simultaneously throwing newly formed brigades and divisions from the territory of the Russian Federation,” Syrskyi said Friday on his Telegram channel.

Syrskyi said Russian forces were trying to “increase the level of combat potential and resume active offensive operations.” He did not provide details but said the Russians continued heavy artillery and mortar shelling as well as air assaults.

“Under such conditions, we must promptly take all measures to strengthen our defenses on the threatened lines and advance where possible,” the general said.

Russia seized Kupiansk, a town with a pre-war population around 27,000, early after the February 2022 invasion, but Ukrainian troops recaptured it in a lightning offensive in September that embarrassed Moscow.

Prigozhin’s death

The Kremlin on Friday labeled as “an absolute lie” the Western conjecture that Russian President Vladimir Putin masterminded Yevgeny Prigozhin’s death.

The chief of the mercenary Wagner Group reportedly was on a jet that crashed Wednesday evening just outside Moscow.

Putin cited “preliminary information” saying that Prigozhin and his top Wagner associates had all been killed.

Earlier Friday, Russian Deputy Foreign Minister Sergei Ryabkov scolded U.S. President Joe Biden for suggesting that the Russian president had orchestrated Prigozhin’s death.

“It is not for the U.S. president, in my opinion, to talk about certain tragic events of this nature,” Ryabkov said.

Speaking with reporters Wednesday, Biden said he was not surprised by Prigozhin’s reported death. “There’s not much that happens in Russia that Putin’s not behind,” he said.

On Friday, Biden said the U.S. was trying to determine on its own what brought the plane down. Asked what caused the plane to crash, he said: “I’m not at liberty to speak to that precisely. … We’re trying to nail [that] down precisely, but I don’t have anything to say.”

Asked by The Associated Press whether the Kremlin had received an official confirmation of Prigozhin’s death, Kremlin spokesperson Dmitry Peskov referenced Putin’s remarks from a day earlier.

“He said that right now, all the necessary forensic analyses, including genetic testing, will be carried out. Once some kind of official conclusions are ready to be released, they will be released,” Peskov said.

According to a preliminary U.S. intelligence assessment, the plane was downed by an intentional explosion. One of the U.S. and Western officials who described the assessment said it had been determined that Prigozhin was “very likely” targeted, and that the explosion had fallen in line with Putin’s “long history of trying to silence his critics.”

The officials, who spoke on the condition of anonymity because they were not authorized to comment, did not offer any details about what had caused the explosion. It was believed by some to have been carried out in retaliation for the Prigozhin-led mutiny in June that posed the biggest challenge to Putin’s 23-year rule.

Assassination attempts against foes of Putin have been common during his nearly quarter-century in power. Whether it was by drinking polonium-laced tea or touching a deadly nerve agent or getting shot at close range, relatives of the victims and the few survivors of such attacks have blamed Russian authorities. The Kremlin has routinely denied any involvement in such incidents, as it did on Friday.

Grain deal

Ukrainian President Volodymyr Zelenskyy held talks Friday in Kyiv with Turkish Foreign Affairs Minister Hakan Fidan regarding the Black Sea grain deal and other related topics.

Turkey is trying to persuade Russia to return to the negotiating table regarding the U.N.-brokered Black Sea Grain Initiative that was guaranteeing the safety of cargo vessels passing through the Black Sea corridor.

“We know alternative routes are being sought [for grain shipments] but we see no alternative to the original initiative because they carry risks,” Fidan told reporters during a rare visit to Kyiv.

Russia has threatened to treat all vessels as potential military targets after pulling out of the U.N.-backed safe-passage deal.

According to U.S. officials, since Russia’s exit from the grain deal, Ukraine, a major grain exporter, has resorted to overland and Danube River routes as effective ways to transport its grain.

“I think we see there are viable routes through Ukraine’s territorial waters and overland, and we are aiming … over the next couple of months to return to exporting at kind of prewar averages from Ukraine,” James O’Brien, head of the U.S. State Department’s Office of Sanctions Coordination, told Reuters in an interview.

Ukraine has begun exporting through a “humanitarian corridor” along the sea’s western coastline near Romania and Bulgaria.

A Hong Kong-flagged container ship stuck in Odesa port since the invasion began was the first vessel to travel that route last week without being fired upon by Russia.

Some information for this report came from The Associated Press, Agence France-Presse and Reuters.