Britain is ramping up military support to Ukraine, with the supply of heavier weapons and armoured combat vehicles.

UK aid is being escalated as the war enters what Foreign Secretary Liz Truss called ‘a new and difficult phase’.

She predicted ‘a more concentrated Russian offensive’ in the days and weeks ahead as she met NATO foreign ministers in Brussels.

The offensive is expected to involve tens of thousands of Russian troops taking on Ukraine forces in the east of the country.

To ensure the protection of Ukrainian troops, Britain will provide armoured vehicles which can withstand explosive devices, rockets and rifle fire, Mail Online reported.

According to sources, the UK has also agreed to send Harpoon anti-ship missiles in a bid to break the Russian navy’s siege of Black Sea ports.

Ukrainian top brass witnessed what vehicles and weapons the UK can provide at a demonstration on Salisbury Plain, Wiltshire, this week.

Among the kit expected to be sent is the biggest of the vehicles from the Army’s ‘Protected Patrol’ fleet – the Mastiff, which weighs 23 tons.

This 6×6 wheel-drive patrol vehicle can carry eight troops and two crew, and was designed to withstand high-grade Improvised Explosive Devices (IEDs) used by the Taliban in Afghanistan.

Such is the level of protection it provides, a defence source last night likened it to the concrete defences built into coastlines during the Second World War.

Other vehicles may include the smaller Ridgback and the faster Husky: Reconnaissance vehicles such as the Jackal may also be sent.

The source said: ‘It is basically like a mobile pill box. You can pretty much fire anything at it in an urban environment and it will keep on going.

‘It is pretty well armed too. This vehicle should prove ideal for the Ukrainians given where the fighting is going to be taking place.’

Other vehicles from the Army’s fleet being considered for deployment include the Ridgback and the Husky.

UK military reconnaissance vehicles such as the Jackal may also be sent, however these offer less protection.

Ukraine is suffering significant shortages of military vehicles and fuel, with Russia using precision air strikes to target fuel depots and oil refineries.

Kyiv’s foreign minister Dmytro Kuleba also attended the Nato talks. Asked what his priorities from the summit were, he replied: ‘Weapons, weapons, weapons.’

He later delivered a dramatic ultimatum, effectively telling Western leaders it was ‘now or never’ to give Ukraine what it needs

Mr Kuleba warned: ‘Either you help us now, and I’m speaking about days not weeks, or your help will come too late and people will die.

‘We know how to fight. We know how to win.

‘But without sustainable and sufficient supplies requested by Ukraine, these wins will be accompanied by enormous sacrifices. The more weapons we get and the sooner they arrive, the more human lives will be saved.’

After failing to capture Kyiv, Russia wants to tighten its grip on the eastern regions, known as the Donbas.

The Kremlin is sending thousands of extra troops to the area which consists of two regions, Luhansk and Donetsk.