Ukraine's Defense Ministry announced the downing of a Russian Sukhoi Su-25 fighter jet in the Donetsk region, while Ukrainian leaders discussed ways to prevent the leakage of military information on U.S. and NATO efforts to help Kiev launch a counterattack.

Ukrainian forces published videos showing the downing of the plane, the moment it fell and exploded, while carrying out raids over the city of Marinka under the control of Ukrainian forces.

Meanwhile, Ukrainian President Volodymyr Zelensky held a meeting of the military high command to discuss the latest developments on the Ukrainian fronts and ways to strengthen them after the formation of new brigades and equipping them with weapons and training.

Ukrainian presidential adviser Mykhailo Podolyak stressed that the Russians will soon see the real plans on the ground, pointing to Moscow's attempt to significantly obstruct the counterattack.

Counterattack leaks

On Friday, Ukraine's leaders discussed ways to prevent the leak of military information after news of classified documents surfaced on social media detailing U.S. and NATO efforts to help Kiev launch a Russian counter-war offensive against Ukraine.

On Thursday, the New York Times quoted senior U.S. officials as saying classified documents about the war were released this week on Twitter and the widely used Telegram application in Russia.

A Ukrainian official told Reuters that the documents contained "a very large amount of false information" and that the social media posts appeared to be a Russian disinformation campaign to question the counterattack, which requires sophisticated Western weapons.

Podolyak said in a statement: "These are just known tools in the games of operations manufactured by Russian intelligence. And nothing more."

The presidential office's announcement of Friday's talks at the Supreme Command of the Armed Forces of Ukraine, attended by Zelenskiy, contained no indication of a leak.

"Participants in the meeting focused on measures to prevent the leakage of information on the plans of the Ukrainian Defense Forces," the announcement said.

It was unclear whether the discussions focused on preventing leaks from inside Ukraine or among Western partners it is currently sharing after initial hesitation following the Russian war.

The New York Times said the documents did not include the date or location of the attack, but the leak could undermine trust between allies, as the document mentioned the timeline for the West to deliver weapons and train Ukrainian forces.

The documents have been modified, apparently in some places, to increase U.S. estimates of Ukraine's war deaths and reduce Russian military casualties, the newspaper said, adding that U.S. officials are working to remove the leaflets.

In Russia, the Kremlin said Russian military commanders were following all information, including statements by US Secretary of State Antony Blinken that Kiev was planning a counterattack.

Field developments

On the ground, local sources in the city of Donetsk reported that one person was killed and others wounded in shelling targeting the city in the Donbas region of eastern Ukraine.

Russian military sites said the Ukrainian shelling of a market in the city centre was carried out by Himars rocket launchers. The pro-Russian Donetsk authorities announced that 9 people were killed when Ukrainian forces shelled the Kalininsky district of the city.

On the situation in Pakhmot, the British Ministry of Defense said in an intelligence assessment that Russian forces have recently regained momentum in the battle for control of the city, and are also significantly threatening the supply line of Ukrainian forces from the west.

"Russia has made more gains, and has now likely advanced to the center of Bakhmut, Ukraine's main supply route 0506 to the west of the city is likely to be severely threatened," the British defense said on Twitter in a periodic bulletin.

The pace of the Russian attack on Pakhmot accelerated in July 2022 after the withdrawal of Ukrainian forces from the Lugansk region adjacent to Donetsk, and the city was subjected to Russian bombardment for several months, and conflicting reports over the past weeks about its control between the two sides of the war.

Ukraine says it is sticking to the city, but the situation is difficult. Zelenskiy said on Wednesday that his forces would withdraw from Bakhmut if they were at risk of being siege.

Pakhmut is one of the last urban centers in the Donetsk region (eastern Ukraine) that has not yet fallen to Russian forces.

Donetsk is one of four regions in eastern and southern Ukraine that Russia annexed last year and is seeking to seize it entirely, in what appears to have changed its goals after failing to overrun the country at the start of the war.

Brazilian initiative

Meanwhile, Ukraine has announced that it will not cede Crimea, which Moscow annexed in 2014 in exchange for an end to the war, rejecting a proposal by Brazilian President Luiz Inácio Lula da Silva.

Ukrainian Foreign Ministry spokesman Oleg Nikolenko wrote on Facebook that "there is no legal, political or moral reason justifying the abandonment of one centimeter of Ukrainian territory," stressing his appreciation for "the efforts of the Brazilian president to find a way to stop Russian aggression."

"Any mediation aimed at restoring peace in Ukraine must be based on respect for the sovereignty and territorial integrity of Ukraine in full, in accordance with the principles of the UN Charter," he added.

Lula suggested on Thursday that Ukraine cede Crimea to Russia in order to end the war, arguing that Ukrainian President Volodymyr Zelensky could not "get everything."

At the end of January, the Brazilian president put forward a still-vague proposal for mediation by several countries in the conflict in Ukraine. Lula is due to present the proposal to his Chinese counterpart Xi Jinping in Beijing next week.

Russia has repeatedly stressed in recent days that talks are currently impossible and vowed to continue its military operation.

Russian Foreign Minister Sergei Lavrov said on Friday that peace negotiations on Ukraine could only be carried out on the basis of establishing a "new world order" that is not dominated by the United States.