Speaking to security chiefs in Berlin, Andrew Parker also condemned Russia for the "reckless" poisoning of the Skripals in Salisbury.

Russia has denied involvement in the poisoning of Russian ex-spy Sergei Skripal and his daughter Yulia.

Mr Parker also warned Islamic State aspires to commit "devastating" and "more complex" attacks in Europe.

In his first public comments about the nerve agent attack in March, Mr Parker accused the Kremlin of "flagrant breaches of international rules".

"The reckless attempted assassination of Sergei Skripal, using a highly lethal nerve agent, put numerous lives at risk, including that of his daughter," he said.

"It was only through near-miraculous medical intervention that his and his daughter's lives were saved, and wider preventive action was able to be taken."