KYIV: Russian forces have rapidly advanced in a narrow but important sector of the front line, the Ukrainian military and analysts said Tuesday, days ahead of a meeting between the Russian and US presidents.

Moscow’s army, which invaded Ukraine in 2022, has made costly but incremental gains across the sprawling front in recent months and claims to have annexed four Ukrainian regions while still fighting to control them.

The Ukrainian army said in a statement on Tuesday that there had been fighting around the village of Kucheriv Yar in the Donetsk region, acknowledging Russian gains.

The Ukrainian DeepState blog, which retains close connections with the military, showed Russian advances around 10 kilometers (six miles) over around two days.

The corridor now under Russian control threatens the town of Dobropillya, a mining town that civilians are fleeing and that has been coming under Russian drone attacks.