Dmitry Kiselyov, a Kremlin supporter and state propagandist, issued the threats Sunday on his state television program.

In a segment called “The Sinkable Island,” Kiselyov taunted British Prime Minister Boris Johnson, accusing him of threatening Moscow with a nuclear strike (something that Johnson has not done, but fits with the Kremlin’s message to Russian citizens that the country is under attack by NATO and the Western world). He then showed an animated graphic striking the British Isles and eliminating them.

“Just one launch, Boris,” Kiselyov said, “and England is gone. Once and for all. Why play with us?”

The comments came after Johnson visited Kyiv last month to show support for the country. In addition, British Foreign Secretary Liz Truss recently said a Ukraine victory was a “strategic imperative” for the West.

Kiselyov also showed a simulation of a second missile, launched from an underwater nuclear-capable drone, which he said could carry up to a 100-megaton warhead.

“The explosion of this thermonuclear torpedo off the coast of Britain will raise a giant wave up to 500 meters high,” Kiselyov claimed. “Such a water squall also carries extreme doses of radiation. Passing over the British Isles, it will turn what may be left of them into a radioactive desert.”

Kiselyov did not offer any evidence for his claims.

While the comments rankled U.K. officials, experts said that Russia does not have a single weapon that’s capable of what Kiselyov claimed, The Washington Post reported.