President Vladimir Putin is “deliberately targeting” civilians in his war in Ukraine, Britain’s ambassador to the country has said.

Melinda Simmons said Russian forces are ramping up the level of violence they unleash every time the Ukrainian military successfully resists, calling the situation “incredibly worrying”.

She told Sky News in an interview on Thursday it was possible that Moscow could escalate to using chemical weapons or even a limited nuclear strike as it has such potential.

But the senior diplomat, who has temporarily relocated to next-door Poland because of the war, said that the focus for her team was on doing everything possible to help Ukrainians deal with the reality they face right now, which is bad enough.

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Asked whether she thought there was a chance of the crisis spilling out beyond Ukraine’s borders and even igniting World War Three, Ms Simmons said it was “too early to say” and she did not want to deal in “Apocalyptic prophecies”.

She added that while it was “perfectly possible”, even the thought of that kind of escalation is part of President Putin‘s narrative…”It is a goading if you like to the West to become involved in this conflict that then if you like almost self-fulfils the prophecy”.

West performing a fine balancing act

One significant way Western allies are involved in the conflict though is through giving weapons to the Ukrainian military to help them fight the Russians.

But the West is performing a balancing act to ensure their contribution does not cross a line that would lead them into a direct military conflict with the Kremlin.

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“The military assistance that we have given Ukraine is all about assistance that enables them to defend themselves,” the British ambassador said, speaking via a video link from Warsaw.

“The live debate of course is as Russia ratchets up that pressure with whatever additional capability Russia puts into theatre so Ukraine’s partners have to think then about how that assistance has to develop in order to be able to continue to help Ukraine defend itself.”

A no-fly zone is an ’emotive’ issue

A major factor is how to respond to increasingly desperate calls from the Ukrainian government for NATO allies to impose a no-fly zone that would prevent Russia from launching airstrikes and missiles against Ukrainian targets.

Ms Simmons said: “It is a hugely emotive issue.”

She described it as “a really difficult judgement for world leaders to make”.

Summing up the dilemma, she said creating a no-fly zone would “bring other countries, including nuclear-capable countries, into conflict with a country [Russia] that is itself a nuclear country.

“So I don’t envy frankly world leaders for having to have that continual debate.”

Asked whether the longer the war continues the greater the risk that allies do need to take that step of creating a no-fly zone and risking direct military confrontation with Russia, the ambassador said: “It is possible, of course, it is possible.”

Ukrainians will not consent to an imposed government

But she stressed that it was also possible the Ukrainians would continue to fight back on their own and even if Russia were to succeed in any kind of occupation they would be drawn into a long-running conflict with Ukrainians “who will not consent to an imposed government and an imposed invasion by Russia. So that too is a scenario”.

Ms Simmons said she believed Russia would hit more civilian targets.

Asked about a Russian attack on Wednesday that struck a maternity hospital in the coastal city of Mariupol, she said: “What it tells me watching this is it is a deliberate targeting of civilians that it is cynical, that there is no way to write this off as an accident, a missile that has gone astray and Russia has form in previous theatres of doing this.”

The envoy said it was hard to say how the crisis would evolve, but predicted more bloodshed.

“It is incredibly worrying… There is no question that the Ukrainians will not continue to fight and there needs to be a point where advisers in Russia understand that enough to articulate that there is no quick resolution to this conflict. There is only one in which many people lose their lives,” she said.

As for whether Russia may choose to escalate the war with a chemical weapons attack – something it has done before, including in Salisbury, she said “I think it is right to be worried about the whole of the Russian playbook.”

Russia’s military doctrine also allows for the use of a tactical nuclear weapon as part of a conventional war.

Asked whether there was a danger that could be deployed in Ukraine, Ms Simmons said: “We know that he has that capability. We just don’t know to what extreme he will go, right, to do it.”

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The UK was one of the first countries to relocate their embassy in the run-up to the war at a time when European allies were playing down the risk posed by President Putin.

Ms Simmons and a reduced team first moved to Lviv, a city in western Ukraine bordering Poland. But they decided to leave the country completely a few days ago for security reasons.

She said that she is determined to return not just to Ukraine but to the capital Kyiv “as soon as I possibly can and safely can”.