Boris Johnson plans a fresh trip to Kyiv to meet Ukrainian President Zelensky

Boris Johnson is planning a trip to Kyiv to visit the Ukrainian president as Russia claimed its first battlefield breakthrough in months.

The former prime minister is a hugely popular figure in the war-torn country, having travelled to Ukraine three times since the conflict began.

Mr Johnson struck up a bond with Volodymyr Zelensky during frequent phone calls while in office, and they are said to regard each other as ‘friends’. He has told allies he intends to return to Kyiv in coming months to show his public support, The Guardian reported.

No10 was said to have been unaware of Mr Johnson’s plans, and a spokesman for Rishi Sunak yesterday declined to comment. But an ally of the PM suggested Mr Johnson was trying to have his ‘Churchill moment’.

Boris Johnson is planning a trip to Kyiv to visit the Ukrainian president Zelensky for the fourth time (Pictured together in August)

They said: ‘This is as much about how Boris views his role on the world stage as it is about backing Ukraine.

‘The situation there remains extremely fragile so he needs to be careful not to compromise Rishi’s relationship with Zelensky.’

A source close to Mr Johnson declined to comment last night, amid speculation that he could become a special envoy to Ukraine. It came as Russia claimed yesterday that its forces had captured the town of Soledar in eastern Ukraine in what would be its first victory in six months.

Ukraine denied that the Russians had control, saying ‘severe fighting’ was ongoing in the key salt mining town. However there were reports of Ukrainian forces being seen withdrawing in an apparent controlled retreat.

The Russian defence ministry said it had ‘completed the liberation’ of Soledar and that the victory would pave the way for more ‘successful offensive operations’ in the Donetsk region. The country claimed Soledar’s capture ‘makes it possible to cut off supply routes of Ukrainian troops’ and surround them.

A source close to Mr Johnson declined to comment last night, amid speculation that he could become a special envoy to Ukraine

But the US Institute for the Study of War called the move a ‘small-scale victory’, which had been ‘overexaggerated’.

Moscow’s last major gains were in June and July with the capture of Lysychansk and Severodonetsk in the eastern Luhansk region. Putin’s forces have since suffered a string of heavy defeats, including its retreat from the southern city of Kherson.

The battle for Soledar comes after a major reshuffle in Moscow, with chief of the general staff Valery Gerasimov now in charge of operations in Ukraine. A Moscow-based analyst, who spoke on condition of anonymity, said the move was ‘unprecedented’ and indicated ‘very serious problems’ for Russia on the battlefield.

Ukrainian defence minister Oleksiy Reznikov meanwhile said the country had effectively become a NATO member despite the alliance’s reluctance to enter into a conflict with Russia.

Mr Reznikov said he was confident Western allies would shed their inhibitions about supplying Ukraine with heavier weapons such as tanks and fighter jets.

‘This concern about the next level of escalation, for me, is some kind of protocol,’ he told the BBC, dismissing NATO fears about provoking Russia.