On 15 September, the UK Ministry of Defence announced that a recruitment campaign had begun in Russian prisons. Prisoners were offered reduced sentences and financial incentives in exchange for joining the Wagner Group. 

On 19 September, during shelling in the Mykolaiv region, a shell landed just 300 meters from the reactors of South Ukraine nuclear power plant, damaging nearby buildings and a hydroelectric station.

On 20 September, the authorities of the self-proclaimed Donetsk People’s Republic and Luhansk People’s Republic announced sham referendums on joining Russia, scheduled to be held from 23 to 27 September 2022. 

The European Council approved a decision to grant Ukraine an additional €5 billion in macro-financial assistance to bolster its immediate resilience. This aid was intended to complement other forms of support for Ukraine, including humanitarian, development, customs, and defence support. €5 billion represented the second phase of the European Union’s planned €9 billion financial assistance package for Ukraine, approved by the European Council on 23-24 June 2022.

On 21 September, after mediation efforts by the President of Turkey, Recep Tayyip Erdoğan, 215 Ukrainian soldiers were released, including 108 members and commanders of the Azov Regiment, who had defended Azovstal in Mariupol.

On 23 September, the exhumation of victims of the Russian occupation in Izium, was completed. A total of 436 bodies were exhumed, the majority showing signs of violent death, and 30 displaying evidence of torture. Law enforcement officials reported finding bodies at the mass burial site with ropes around their necks, bound hands, broken limbs, and gunshot wounds. Oleh Sinehubov, head of the Kharkiv administration, reported, among other things, that several men had their genitals amputated. All of this serves as evidence of the horrific torture inflicted on Izium residents. A total of 427 bodies were recovered, including 202 women and five children. Additionally, a mass grave containing the remains of 17 Ukrainian soldiers was uncovered. 

G7 leaders condemned the sham referendums, which Russia sought to use as a false pretext to alter the status of Ukraine’s sovereign territory. They stated that such actions clearly violated the United Nations Charter and international law, and contradicted the principles of the rule of law.