By Michael Drummond, foreign news reporter

Ukraine’s counteroffensive is now into its fourth month. Kyiv’s forces, bolstered by Western tanks and weapons, are putting pressure on Russian positions but have yet to achieve a major breakthrough.

For our latest series in the Ukraine live blog, we are taking a look at five key locations along the 745-mile front line…

Part three: Is Russia pushing back in Kharkiv?

One of the main efforts of Russian forces – apart from holding back Ukrainian advances – is trying to take territory in the northeast, near Kharkiv.

Ukraine had great success in that arena last year, carrying out stunning advances around Kharkiv city.

Not only did they buy valuable breathing space for the “Hero City”, they also liberated swathes of territory, including Kupyansk and Izium.

Now Russian troops are seeking to reverse some of those gains.

“The lines of communication there are very short for the Russian forces,” military analyst Sean Bell says.

This is because of how close things are to the Russian border. Unlike in other parts of Ukraine, it’s much easier for Russia to resupply and communicate with its troops in the Kharkiv region.

In recent weeks they have claimed to have made advances, and fighting has been fierce and bloody.

Bell adds: “Russia has not been effective at conducting offensive operations since the start of the war – and that was when they had mercenary support with the Wagner Group.

“So it’s no great surprise that the Russian military are struggling to make progress.”

Check back at 12.30pm tomorrow for part four of this series