European Commission President Jean-Claude Juncker has admitted that he has not yet joined the smartphone revolution.

Speaking as he helped launch the EU presidency of Estonia, he said: "I shouldn't say but I have to say it, I still don't have a smartphone."

The 62-year-old head of the EU's executive arm was speaking at a news conference in the Baltic state's capital, Tallinn.

"So I couldn't become prime minister of Estonia, this would be totally impossible," Mr Juncker said alongside a smiling Estonian premier Juri Ratas.

He added that Mr Ratas was aware of his lack of a smartphone, "which is why he sent me, like in the 19th Century, a postcard inviting me to Tallinn."

Mr Juncker, a former Luxembourg prime minister, uses an old Nokia mobile phone, EU sources told AFP.

Estonia, one of the world's most digitally connected countries, said it would push digital issues as part of its six-month stint as president of the EU, which begins Saturday.

Mr Ratas said he wanted the free flow of information to become the EU's "fifth fundamental freedom", after the freedom of movement for people, goods, capital and services, the pillars of the 28-nation bloc's single market.

Mr Juncker said he counted on Estonia's "leadership" in the months ahead.

"Even without being a techie I know that our future is digital. Digital is the DNA of your country and it needs to become part of the European DNA," Mr Juncker said.

But in the wake of a huge global cyberattack which spread from Ukraine to hit several countries this week, security was also a priority, he said.

"Success of the digital single market will also depend on the confidence of Europeans. That is why I hope we can learn from your experience on cybersecurity, the scale of the risks is significant," Mr Juncker said.

Estonia was the first state to be hit by a massive cyberattack, in 2007, which paralysed key corporate and government web services for days.

Estonia blamed Russia, which denied the charge.