Russian officials threatened the West on Sunday with a “severe” response in the event that frozen Russian assets are confiscated, promising “endless” legal challenges and tit-for-tat measures.

Russian Foreign Ministry spokeswoman Maria Zakharova said Russia would never cede territories seized from Ukraine in exchange for the return of frozen assets.

“Our motherland is not for sale,” Zakharova wrote on the Telegram messaging app.

“An Russian assets must remain untouched because otherwise there will be a severe response to Western thievery. Many in the West have already understood this. Alas, not everyone.”

In response to Russia’s war in Ukraine, the United States and its allies prohibited transactions with Russia’s central bank and finance ministry and blocked about $300 billion of sovereign Russian assets in the West, most of which are in European not American financial institutions.

Kremlin spokesman Dmitry Peskov said in a separate comment that there was still a lot of Western money in Russia which could be targeted by Moscow’s counter-measures.

“The prospects for legal challenges (against the confiscation of Russian assets) will be wide open,” he said. “Russia will take advantage of those and will endlessly defend its interests.”