Senior Ukrainian officials say Vladimir Putin is preparing for a major new offensive in the new year, despite a series of humiliating battlefield setbacks for Russia in recent months.
The briefings appeared to be part of a broad, coordinated effort to warn against complacency among western allies and highlight the continuing threat Russia poses to Ukraine.
While Reznikov suggested a new offensive could happen by February, the other senior officials indicated they believed it might come as early as January.
In another briefing on Thursday, the deputy defence minister Hanna Maliar also warned against allowing complacency to set in after recent Russian military setbacks.
The aim was to debilitate Ukraine to increase the chances of success on the battlefield. However, since then, Ukraine has shown increasing skill in shooting down rockets and drones.
Ukraine has also been appealing for new weapons systems including better air defences, even as it appears to have escalated its targeting of bases in Russia, including with drones, strikes Reznikov declined to comment on.
Ukraine was using a combination of air defence systems gifted by its partners, Soviet-era systems and repurposed mobile machine guns to combat the threat, said Reznikov. On Tuesday, CNN reported that US officials had agreed to send Ukraine powerful and effective US-made Patriot air defence systems that Ukraine has been asking for for months.
The US had previously worried the long-range Patriot defence systems, which can travel up to 60 miles, would provoke an escalation from Russia.
The series of wins had created something that transcended diplomatic trust between Ukraine and its partners, said Reznikov.
The comments came as fighting continued on the southern and eastern fronts. In the south, Russian shelling on Thursday killed two people in the city of Kherson and left it without power, Ukrainian officials said, in the latest bombardments since Kyiv recaptured the city last month.
