As leaders from the world of politics and business arrive Tuesday in droves for the start of the World Economic Forum in the Swiss ski resort of Davos, the event's founder is in somber mood.

Klaus Schwab, the 77-year-old chief of the world's most recognized annual economic meeting, said he's worried about Europe's future, the fallout from plunging oil prices and gaping inequalities worldwide.

In an interview with The Associated Press, Schwab also justified the decision of the WEF to disinvite a delegation from North Korea, including its foreign minister, for its claim earlier this month that it had tested a hydrogen bomb. The WEF has been working hard to bring the North Koreans to the 45-year-old annual gathering at the highest level since the 1980s.

"We had to show solidarity with the global world opinion," Schwab said late Monday. "We never cede to any pressure, but we have one principle which means that we observe U.N. sanctions. We do not know yet how the U.N. sanctions will come out, but we didn't want to have the coincidence of the U.N. expressing sanctions — tough sanctions — this week and at the same time, we act against those sanctions."

Schwab said he was "very much looking forward" to the arrival of the North Korean delegation and laid out his hope that the country would qualify one day "hopefully sooner rather than later."

The revocation prompted a sharp letter of retort by its ambassador in Geneva, but Schwab insisted Davos organizers had little choice amid a growing prospect of new sanctions against Pyongyang.

With the world facing a myriad of problems such as climate change and war, Schwab said he wanted a "forward-looking" theme to dominate discussions this year, which officially runs from Wednesday through to Saturday: and has built this edition around the idea of the Fourth Industrial Revolution.

He said vast, speedy technological advances in the digital age in areas like nanotechnology and automation threaten to leave many unskilled workers without jobs or at an economic disadvantage.

In Davos, about two-thirds of the 2,500-plus attendees are decision-makers from the business world: The boardroom, not the shop room floor, has an outsize representation in this snow-capped, ultra-chic Alpine resort. World leaders, including U.S. Vice President Joe Biden, Prime Ministers David Cameron of Britain and Nawaz Sharif of Pakistan, and German President Joachim Gauck are set to attend.

Iranian Foreign Minister Mohammad Javad Zarif is likely to be a headline-act after international sanctions against his country were lifted over the weekend under a deal on Tehran's nuclear program. Some business leaders will be contemplating a resumption of economic ties with the long-isolated, oil-rich Islamic republic.

Iran's Oil Ministry announced plans Monday to boost oil production by 500,000 barrels per day after the sanctions were lifted, and Schwab noted the possible harmful impact of even more supply on developing countries that depend on oil revenues at a time when crude prices have already slumped to their lowest level in more than 12 years.

"Of course, we will have to absorb now a larger supply dimension. What concerns me is the impact — the social impact — it has on certain countries," said Schwab. "Just think of Nigeria, which so much depends on oil, and other African countries ... not to speak about what's the impact on Russia and so on."

As for Europe's struggle to manage an influx of more than 1 million refugees and migrants last year, he said the continent was at a "crossing point." Europe needs to find the right balance between its values and its capabilities of taking them in, and assuage tensions that have put the Schengen zone — which eases cross-border travel — to the test, he said.

"My concern is that Europe, at the moment, is in a phase of disintegration," Schwab said. "Europe would be completely marginalized if we break up into different nation-states again."

He said solidarity with refugees was a core European value.

"It's not a question whether we should have solidarity or not, it's how much can we afford? And here I think we haven't found the right answer yet," he said.

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