Western nuclear powers France, Britain and the US have refuted Russia's claims that Ukraine is planning to detonate a nuclear-tipped bomb on its own territory.

The claim about a so-called "dirty bomb" is clearly wrong, according to a joint statement by the foreign ministers of the countries early Monday morning. "The world would see through any attempt to use this claim as a pretext for escalation."

According to his ministry, Russia's Defense Minister Sergei Shoigu had previously told the European nuclear powers Great Britain and France that Kyiv was planning to detonate a radioactive bomb to discredit Moscow. The Turkish Defense Minister Hulusi Akar also received a call from Shoigus. British Defense Secretary Ben Wallace said after his phone call with Shoigu that he had denied the allegations. US Secretary of State Antony Blinken also wrote on Twitter that the Russian allegations were false.

Kuleba: Russia's claims absurd and dangerous

Conventional explosive devices that also scatter radioactive material are referred to as "dirty bombs". Ukraine gave up its nuclear weapons after the collapse of the Soviet Union. "Russian lies about Ukraine's alleged plans to use a 'dirty bomb' are as absurd as they are dangerous," Foreign Minister Dmytro Kuleba responded on Twitter.

Ukraine is loyal to the Nuclear Non-Proliferation Treaty. "The Russians often blame others for what they are planning themselves," Kuleba warned in Kyiv.

In their letter, France, Great Britain and the USA assured Ukraine that they would continue to provide humanitarian aid as well as economic and security support to Ukraine. "We remain committed to continuing to support Ukraine's efforts to defend its territory for as long as necessary."

Despite Western skepticism, Russia is sticking to the claim that Kyiv wants to discredit Moscow by detonating a "dirty" - that is, a nuclear-contaminated - bomb.