"We are increasing production of the most powerful means of destruction. Including those based on new principles," Medvedev said on messaging app Telegram.

"Our enemy dug in not only in the Kyiv province of our native Malorossiya," Medvedev said, using the term to describe territories of modern-day Ukraine that were part of the Russian Empire under the tsars.

"It is in Europe, North America, Japan, Australia, New Zealand, and a whole number of other places that pledged allegiance to the Nazi."

Medvedev, who serves as deputy head of Russia's Security Council, did not provide details of the weapons.

President Vladimir Putin repeatedly said that Russia has been developing new types of weapons including hypersonic weapons that he boasts can circumvent all existing missile defence systems.

Since Putin sent troops to Ukraine on February 24, 57-year-old Medvedev has regularly taken to social media to write increasingly bombastic posts.

With Moscow on the back foot in its offensive in pro-Western Ukraine, the military stalemate has raised fears that Russia could resort to its nuclear arsenal to achieve a military breakthrough.

On Friday, Putin said Russia could amend its military doctrine by introducing the possibility of a preemptive strike to disarm an enemy, in an apparent reference to a nuclear attack.

The Kremlin chief claimed that Russia's cruise missiles and hypersonic systems were "more modern and even more efficient" than those in the United States.