The deputy secretary of Russia’s Security Council said Western military aid would not stop Moscow’s victory in Ukraine.

Commenting late on Tuesday as the first day of the NATO summit in Lithuania wrapped up, Medvedev said that pledges of military aid from the Western defence alliance to Kyiv would not deter Russia from achieving its goals in Ukraine. Russia’s foreign minister issued similar warnings that Moscow had no intention to end its war.

“The completely crazy West could not come up with anything else … In fact, it’s a dead end. World War Three is getting closer,” Medvedev wrote on the Telegram messaging app.

“What does all this mean for us? Everything is obvious. The special military operation will continue with the same goals,” he said, using the official Russian name for its full-scale invasion of Ukraine.

Medvedev, who had cast himself as a liberal moderniser when he was Russian president from 2008-2012, has more recently presented as a fiercely anti-Western Kremlin hawk. In January, he threatened that defeat in a conventional war in Ukraine could lead to a nuclear war. Diplomats say his views give an indication of thinking at the top levels of the Kremlin elite.

According to Russia’s state-run TASS news agency, Medvedev also said that Moscow’s goal of preventing the “neo-Nazi group” in Kyiv from joining NATO was now “impossible” and removing the Ukrainian government was necessary.

“We insisted on that from the very outset, but it is impossible, and, therefore, this group has to be eliminated. This is possible and necessary,” Medvedev said, according to TASS.

Russia’s Foreign Minister Sergey Lavrov also said on Tuesday that the war in Ukraine would not end while the West used Ukraine as a proxy to inflict a strategic defeat on Moscow.

“Why doesn’t the armed confrontation in Ukraine come to an end? The answer is very simple: It will continue until the West gives up its plans to preserve its domination and overcome its obsessive desire to inflict on Russia a strategic defeat at the hands of its Kiev [Russia’s spelling for Kyiv] puppets,” Lavrov said in an interview with Indonesian media, according to TASS.

“For the time being, there are no signs of change in this position,” Lavrov said.

Medvedev also advocated on Tuesday for using cluster munitions, which he called an “inhuman weapon”, after what he said were reports of Ukraine already using them in battle.

The United States announced last week that it would supply Kyiv with cluster munitions, which typically release large numbers of small bomblets over a wide area and are banned by many countries because of the danger they pose to civilians during and after conflicts.

Russian Defence Minister Sergei Shoigu also said on Tuesday that Moscow would use “similar” weapons in Ukraine if the US supplied Kyiv with cluster bombs.

Shoigu also warned that Russian cluster weapons are “much more effective than the American ones, their range is wider and more diverse”.

Russia and Ukraine have accused each other of already using cluster munitions on the battlefield.