Vladimir Putin has said “we haven’t gone mad” when asked about concerns he could use nuclear weapons in Ukraine – but didn’t rule out a possible first-strike if threatened.

The Russian president described the weapons as a deterrent, but reiterated his country would use “all the means at our disposal” to defend its interests if “peaceful means” were to fail.

It is the latest in a number of statements since the start of the war in which he has kept open the nuclear option.

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“We haven’t gone mad. We fully understand what nuclear weapons are,” Mr Putin told a member of the presidential Human Rights Council in televised comments.

“We have them, and they are more advanced and state-of-the-art than what any other nuclear power have,” he said.

“We aren’t going to brandish those weapons like a razor running around the world, but we naturally proceed from their existence.

“It’s a factor of deterrence, not a factor provoking an escalation of the conflict.”

The president none-the-less declined to rule out a theoretical first-strike, claiming it could stop Russia defending itself.

He said Russia had a “launch on warning” doctrine, whereby Russia would fire nuclear weapons if targeted by an imminent nuclear attack – or by a conventional attack that threatened its existence.

“If it doesn’t use it first under any circumstances, it means that it won’t be the second to use it either, because the possibility of using it in case of a nuclear strike on our territory will be sharply limited,” the president said.

Many Western countries have previously criticised Mr Putin’s nuclear comments as dangerous.

However, he claimed on Wednesday he had been provoked by former UK prime minister Liz Truss when she spoke about her own readiness to use nuclear weapons.

He appeared to be referring to comments by Ms Truss in August in which she told a Tory hustings event she would be “ready” to use WMDs if necessary.

“I had to emphasise certain things in response,” said Mr Putin.

“Her comments went largely unnoticed, but they immediately emphasised our statements and used them to scare the world.”

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His remarks echoed ones from October, when he said Ms Truss was “a bit out of it” when she raised concerns over Russia’s nuclear capability in a UN speech.

Mr Putin also spoke about the status of the Ukraine war, where it has lost significant ground in recent months, and admitted it would likely be a “long process” – suggesting Russia has no plans to abandon the conflict any time soon.

He also tried to put to rest rumours of a second mobilisation next year, saying there was no need to conduct an additional call-up.

The Russian president said that of the 300,000 reservists drafted, about half had been sent to the zone of what Moscow calls its “special military operation” in Ukraine.

Some 77,000 were in combat units and the rest were performing defensive functions, he said.

Rumours have been growing among Russian opposition politicians and prominent pro-war Telegram channels of a second wave early next year.