A third world war would be 'nuclear and destructive', a Russian minister has warned.
Sergei Lavrov, the Russian Foreign Minister, said on Wednesday that if a third World War were to take place, it would involve nuclear weapons and be destructive, the RIA news agency reported.
Lavrov has said that Russia, which launched what it called a special military operation against Ukraine last week, would face a 'real danger' if Kyiv acquired nuclear weapons.
His comments come as UK Defence Secretary Ben Wallace warned Russia would likely use indiscriminate carpet bombing against Ukrainian cities as Vladimir Putin's forces close in on the capital, Kyiv - and again rejected calls for RAF jets to enforce a no-fly zone.
The Russian President, Mr Wallace said, knows 'no limits'.
And he said the leadership of the Russian military was 'ruthless' and prepared to lay 'siege' to cities and towns.
A former Nato commander, meanwhile, said a Nato no-fly zone couldn't be imposed on Ukraine because it 'would lead to the third world war'.
Russian troops have entered Ukraine’s second city Kharkiv following days of intensive bombardment, but Mr Wallace said Mr Putin's forces were not yet in control of it.
The Ministry of Defence said the latest intelligence suggested Russian forces had reportedly moved into the centre of Kherson in south Ukraine.
Artillery and air strikes have targeted built-up areas in Kyiv, Kharkiv, Mariupol and Chernihiv.
But Mr Wallace said the advance of Russian forces continued to be slowed by a combination of overstretched logistics, poor morale and brave resistance by Ukrainian fighters.
He told Sky News that Russian advances were being hampered by resistance they had seen 'footage of Ukrainians using UAVs to attack petrol train convoys, to go after logistical lines, we have seen railway lines blown up', but there had also been a switch in Moscow’s tactics as a result.
"What you are seeing now is those heavy bombardments at night, they won’t come into the cities as much, they will – I’m afraid, as we have seen tragically by the looks of things – carpet-bomb cities, indiscriminately in some cases," he said.
"They will fly their air at night rather daytime because what we have seen is they get shot down in the daytime and they will slowly but surely try and surround the cities and then either bypass them or bombard them.
"That is the brutality I’m afraid we are witnessing and it’s going to get worse."
Mr Wallace warned a no-fly zone would trigger a Europe-wide conflict and could also hamper the Ukrainian forces' ability to counter Russia's military.
He told Sky News: "If you have a no-fly zone you have to enforce a no-fly zone.
"That would involve British fighter jets shooting down Russian fighter jets, probably over Ukraine, that would lead to Article Five triggering of Nato and Nato is a self-defence pact, all 30 countries will come to each other’s aid, the triggering of that Article Five would lead to a war against Russia across the whole of Europe."
General Sir Adrian Bradshaw, Nato’s former deputy supreme allied commander, has said Nato cannot impose a no-fly zone on Ukraine as this would lead to the 'third world war'.
He told BBC Radio 4’s Today programme: “This is not like Iraq; we’re up against sophisticated enemy with very capable air defence assets.
“This becomes a struggle between the forces of Nato and the forces of Russia, on the ground, quite probably from the sea, in the air, in the space domain, in the information domain and in the cyber domain.
“This is war. It amounts to 30 countries against Russia. This is the third world war in anybody’s language.
“We cannot afford to let that happen,” he added.
