LONDON, February 17. /TASS/. Former chief of the British intelligence service MI6, John Sawers, has issued a warning against a buildup of pressure on the Russian President Vladimir Putin in connection with developments in Ukraine.

As he addressed students at King’s College in London, Sir John said "provoking" Putin could deepen the security crisis Europe is facing. The west would have to learn to live with Putin, he said.

"The Ukraine crisis is no longer just about Ukraine," The Guardian quoted him. "It’s now a much bigger, more dangerous crisis, between Russia and western countries, about values and order in Europe."

Sawers recalled that Russia had "a formidable nuclear arsenal" and added: "We deal with the Russia we have, not the Russia we’d like to have."

He said the West could take on Moscow by stepping up its "response", providing weapons to Ukraine and tightening up sanctions. "But how would Mr. Putin respond?" Sawers asked.

"As long as Mr Putin sees the issue in terms of Russia’s own security he will be prepared to go further than us," he said.

"Managing relations with Russia will be the defining problem in European security for years to come," Sawers claimed.

"Sawers’ remarks reflected the overwhelming view in Britain’s national security establishment which, with the exception of some former generals, is urging caution over Ukraine," The Guardian said.