LONDON: The head of British intelligence agency MI5, Andrew Parker, on Monday warned of Russia acting in "increasingly aggressive ways" and utilising new technologies in its opposition to the west.
"It is using its whole range of state organs and powers to push its foreign policy abroad in increasingly aggressive ways -- involving propaganda, espionage, subversion and cyber-attacks.
"Russia is at work across Europe and in the UK today. It is MI5's job to get in the way of that," Parker told the Guardian newspaper.
The director general of the UK's domestic security service was speaking after British warships earlier this month shadowed a Russian aircraft carrier battle group through the North Sea, which was en route to the eastern Mediterranean.
Defence Minister Michael Fallon said the Russian naval deployment was "clearly designed to test" British and broader NATO capabilities.
Last month Britain scrambled fighter jets from an airbase in Scotland as two Russian bombers neared, but did not enter, UK airspace.
Parker said Russia was increasingly positioning itself against the west and making use of non-traditional methods to do so.
"Russia increasingly seems to define itself by opposition to the west and seems to act accordingly," he said.
"You can see that on the ground with Russia's activities in Ukraine and Syria.
"But there is high-volume activity out of sight with the cyber-threat. Russia has been a covert threat for decades. What's different these days is that there are more and more methods available," Parker added.
The spy chief's comments follow the US earlier this month accusing Russia of trying to interfere in the upcoming presidential election by hacking US political institutions, charges the Kremlin has repeatedly dismissed.
A focal point of strained relations between Russia and the west has been Syria, where Moscow is backing the regime of President Bashar al-Assad.
The Syrian conflict began in March 2011 and has since killed more than 300,000 people, with fighting most recently centring on the country's second city Aleppo.
Britain's foreign minister, Boris Johnson, earlier this month said the government had evidence Russian jets had been involved in bombing raids which hit aid workers.
"We are trying to document that fully because that is in my view unquestionably a war crime," he told The Sun newspaper.
"The world's attitude towards Russia has been hardening and I think people now believe that Russia is in danger of becoming a pariah nation," Johnson added.