British Prime Minister David Cameron insisted he was not turning his back on Europe as he came face to face with world leaders for the first time since unveiling plans for an EU referendum.

The global elite gathered at the World Economic Forum in Davos on Thursday and discussed issues ranging from the civil war in Syria and the conflict in Mali to the need to counter tax avoidance by multinational corporations.

But the hot topic at the snowy Swiss ski resort was Cameron's relations with his European Union partners, one day after he unveiled his controversial proposal to let the British public vote on whether to stay in the bloc.

Cameron held talks with German Chancellor and EU powerbroker Angela Merkel and the prime ministers of Ireland, Italy and the Netherlands at the annual forum as he tried to win their backing for his plans.

"This is not about turning our backs on Europe -- quite the opposite," Cameron told the audience of business leaders, top politicians and journalists.

"It's about how we make the case for a more competitive, open and flexible Europe and secure the UK's place within it."

Back home Cameron's announcement on Wednesday that he wants to renegotiate Britain's relationship with Brussels and then hold an "in-or-out" referendum on membership by the end of 2017 has delighted his increasingly anti-EU party.

In an poll of 2,000 people published in Friday's edition of The Times newspaper, 40 percent said that if a referendum were held today they would vote to leave, while 37 percent would want to stay and 23 percent were undecided.

European leaders in Davos called on Britain to remain in the 27-nation group and made encouraging noises in public, but there were signs he has a mountain to climb to convince them of his case.

Dutch premier Mark Rutte warned that without the EU, Britain would be "an island somewhere in the middle of the Atlantic Ocean, somewhere between the United States and Europe".

Irish Prime Minister Enda Kenny said the EU would be "stronger if Britain is part of it".

From Lisbon, Portugal's Foreign Minister Paulo Portas said: "We would have liked to have had a United Kingdom taking an active part in Europe."

Merkel meanwhile reached out to Cameron by vowing more action on one of the key reforms he wants for Europe -- boosting competitiveness.

"I say this expressly to my colleague David Cameron. You too have addressed competitiveness, see this as a central issue to ensure Europe's prosperity for the future," she said.

Former US secretary of state Henry Kissinger told the forum that the "idea of European unity needs to be resolved" for the continent to fully recover from the three-year eurozone debt crisis.

But Cameron rejected any idea of a European superstate or of Britain ever adopting the euro and added that he did not agree that "there should be a country called Europe".

Cameron said in his speech that Britain's presidency of the Group of Eight leading world economies -- Britain, Canada, France, Germany, Italy, Japan, Russia and the United States -- would focus on tackling tax avoidance.

He said multinational corporations must "pay their fair share" of taxes and that too many businesses were abusing tax schemes.

UN Secretary General Ban Ki-moon urged members of the Security Council to "overcome the deadlock" and find a solution to the bloodshed in Syria, where 60,000 people have died in the past 22 months.

Russia and China have blocked three previous resolutions threatening sanctions against Syrian President Bashar al-Assad but Ban said letting the conflict go on was an "abdication of our collective responsibility to protect".

Ban also called for the world to help end the crisis in Mali, where a French-led military offensive against Islamist militants is under way.

Davos lived up to its reputation as a venue where deals are sewn up on the sidelines as Ukraine and global oil giant Royal Dutch Shell signed a $10-billion shale gas deal.

The invitation-only meeting is also known for its lavish cocktail parties -- but with the glitzy guest list comes tight security, with around 5,000 police and military guarding the venue and helicopters buzzing overhead.