The use of nuclear weapons in Vladimir Putin's war on Ukraine would only backfire on the Russian leader, an expert has said.

Dmitri Alperovitch, who chairs US-based geopolitics think-tank Silverado Policy Accelerator, said Putin's attempts to use the threat of nuclear weapons as a blackmail tool have so far been unsuccessful.

He added that if you look at the trajectory of the Russia-Ukraine conflict, military equipment the US and allies have been opposed to sending to Ukraine - such as tanks, longer-range missiles, and other capabilities - have been provided over time.

Mr Alperovitch told GB News: "Ultimately, using a nuclear weapon does not actually achieve any strategic objectives for Russia other than make the situation much, much worse for [Putin]."

Putin has warned NATO previously not to go too far in its military support for Ukraine or the military alliance would risk a conflict with Russia which could turn nuclear.

Russia has carried out tactical nuclear weapons drills inside its own territory and with key ally, Belarus. Moscow sought to justity those moves by describing them as a response to the West considering sending NATO troops to Ukraine and letting Kyiv target Russia with longer-range weapons.

Heather Williams, Senior Fellow at US-based Center for Strategic and International Studies, told PBS reliance on nuclear threats is an "enduring trend" from Russia.

She added: "Russian leadership may be assuming it has more at stake in Ukraine than NATO and nuclear threats are one means of signaling its commitment to winning the war in the hopes of scaring off Western intervention."

Putin has said Russia doesn't need to use nuclear weapons to win its war in Ukraine, but he warned escalation could lead to "grave consequences".

According to PBS, a Kremlin-linked security expert urged Putin in June to "aim a nuclear pistol" at Russia's Western "adversaries".

The Russian leader said he could see no security threats that would warrant using nuclear weapons, but indicated Russia was mulling changes to its nuclear doctrine.

Russia describes its nuclear weapons as a means of deterrence and says it takes all necessary efforts to reduce the nuclear threat and prevent aggravating relations with other countries which could trigger military or nuclear conflicts.

Senior Russian diplomat, Sergei Ryabkov, is reported to have argued that the war in Ukraine shows Russia's "nuclear deterrence in its traditional sense is not fully working", according to a report in Eurasianet.

Russian Foreign Minister Sergey Lavrov last week revealed the Kremilin was "clarifying" its nuclear doctrine, the official RIA news agency reported.

Lavrov’s comments came amid attempts by US President Joe Biden's Administration to downplay the significance of recent updates to the United States' Nuclear Weapons Employment Planning Guidance.

It now recognises the possibility of coordinated nuclear challenges from Russia, China, and North Korea, according to Eurasianet.

Russia has more than 5,500 nuclear warheads while the US has some 5,044. The US withdrew from an Intermediate-Range Nuclear Forces Treaty in 2019. Russia has declared the deal to be "dead".