Russia will retaliate against NATO countries that facilitate long-range missile strikes against Russian territory by Ukraine, foreign intelligence chief Sergei Naryshkin said.
Naryshkin said changes announced by President Vladimir Putin to Russia's nuclear doctrine meant it was in effect impossible to defeat Russia on the battlefield.

"Our enemies are forced to admit that the determination of the Russian president to firmly defend the country's fundamental interests by all available means narrows the room for manoeuvre for Washington and Brussels,"

"Attempts by individual NATO allies to participate in providing for possible long-range strikes with Western weapons deep into Russian territory will not go unpunished."

Ukraine used U.S. ATACMS missiles to strike Russian territory

On the same day, Putin approved a policy document that lowers the threshold for Russia to use nuclear weapons in response to attacks by an enemy using conventional weapons.