“These tactics can yield incremental gains, but they are poorly suited to achieving operationally significant breakthroughs. Larger assaults have proven costly to Russian forces, which cannot afford sustained equipment losses of the kind seen earlier in Avdiivka,” Michael Kofman, a senior fellow at the Carnegie Endowment, said.

Following a recent field research trip to the country, Mr Kofman said that Ukraine faces tough months ahead despite the improving battlefield situation

He said: “Ukraine faces difficult months of fighting ahead, but the situation at the front is better than it was this spring.

“Ukraine’s manpower, fortifications, and ammunition situation is steadily improving. Russian forces are advancing in Donetsk, and likely to make further gains, but they have not been able to exploit the Kharkiv offensive into a major breakthrough.”