The head of Russia's State Duma, Vyacheslav Volodin, has warned that if Western governments were to provide Kyiv with nuclear weapons, a nuclear conflict could follow in the heart of Europe and it could "disappear".

No Western countries have suggested supplying Ukraine with nuclear weapons in the face of Russia's invasion and nor has Kyiv sought them. Western countries have shown reluctant to provide even some of the heavier conventional weapons that Ukraine is seeking.

But former Polish Foreign Minister Radoslaw Sikorski, who is now a member of the European Parliament, reportedly told Ukrainian online television channel Espreso TV that the West has the right to give Ukraine nuclear warheads to protect its independence, as shown in a video shared by Belarusian media outlet Nexta on Twitter.

Sikorski said Western countries would have this right because Russia had violated the Budapest Memorandum on Security Assurances of 1994. In that year, Ukraine agreed to give up all nuclear weapons left in the country after the fall of the Soviet Union and to join the Treaty on the Nonproliferation of Nuclear Weapons.

In December 1994, Kyiv signed the Budapest Memorandum with Russia, the U.S. and the U.K., in which the signatories pledged to respect the sovereignty, independence and existing borders of Ukraine in exchange for the country's commitment to denuclearize.

In the interview with Espreso TV, Sikorski argued that Russia broke the terms of the deal by invading Ukraine.

Newsweek has contacted Poland's Ministry of Foreign Affairs for comment on Sikorski's statement, which has not been officially supported by the Polish government.

The Polish MEP's words reached Russia, where his declaration was met with scorn by Volodin, who leads one of the chambers of the Russian parliament.

"With such deputies, the Europeans will have much more serious problems than those they have already faced today (refugees, record inflation, energy crisis)," Volodin wrote on his Telegram channel on Sunday.

"Sikorski provokes a nuclear conflict in the center of Europe. He does not think about the future of either Ukraine or Poland. If his proposals are implemented, these countries will disappear, as well as Europe. He needs to be examined by a psychiatrist, pass the mandate and stay at home under supervision," Volodin added.

"It is because of people like Sikorski that it is necessary to liberate Ukraine not only from the Nazi ideology, but also to demilitarize it, ensuring the country's non-nuclear status," the lawmaker concluded.

Newsweek has contacted Russia's Ministry of Foreign Affairs for comment. Russia has warned the West that its supplies of weapons to Ukraine are inflaming the conflict.