No signs so far of Russia intending to nuke Ukraine - GCHQ
Like other U.S. and western officials recently, Sir Jeremy Fleming did not suggest there had been any signs of suspicious activity as he spoke on BBC Radio 4's Today programme, Ukrinform reports.
The top intelligence official warned that any talk of nuclear weapons was "very dangerous".
GCHQ would hope to see "indicators" if Russia planned to use them, he said.
"It's clear to me that whilst we might not like and in many ways abhor the ways the Russian military machine and President Putin are conducting this war, they are staying within the doctrine that we understand for their use, including for nuclear weapons."
He added: "I'm sure Putin's worried about the dangers of escalation. He thinks about those in different terms. But I think it is a sign that he has not reached for these other forms of waging war."
As Ukrinform reported earlier, the Pentagon had received no information that would suggest the Kremlin leader was going to move beyond his threats to employ nuclear weapons in the war he is waging on Ukraine.