Britain may send armoured Land Rovers on a mercy mission to the besieged city of Mariupol, Boris Johnson has said.

The Prime Minister said the UK was looking at “going up a gear” in its support for Ukraine, including possibly sending the armoured vehicles to help provide humanitarian relief to encircled cities.

The southern Ukrainian city has been the target of heavy Russian bombardment. Last week, Emmanuel Macron, the French president, said he would speak to Vladimir Putin to organise an “exceptional humanitarian operation” alongside Turkey and Greece to evacuate it.

It would have marked the first time foreign troops had entered Ukraine since the conflict began, but Mr Macron was told by Putin on Tuesday that the shelling of Mariupol would only cease when Ukrainian troops defending it surrendered.

A Kremlin statement said: “It was stressed that in order to resolve the difficult humanitarian situation in this city, Ukrainian nationalist militants must stop resisting and lay down their arms.”