DAVOS, Switzerland - The global economy and geopolitical tensions are taking a back seat to a more immediate problem at this year's Davos summit of political and business leaders: Heavy snow is burying the venue.

High in the Swiss alps on Monday, on the eve of the opening sessions, many of the roughly 3,000 delegates struggled to reach the ski resort. Part of the main train line into Davos had been buried in snow over the weekend, forcing people onto buses, and helicopters were disrupted by poor visibility.

Some pre-summit meetings were canceled or delayed as the first waves of delegates waded through snow-blanketed streets with luggage, looking for their hotels, or had to wait for road crews to dig their limousines out of drifts.

Businessmen slipped over on icy patches as snow plows roamed the streets, with the snow returning as fast as the machines could clear it.

World Economic Forum communications chief Adrian Monck said it appeared to be the heaviest snowfall for the four-decades-old summit since 1999-2000, though he described it as more of an inconvenience than a real threat to attendance.

"We know the snow causes inconvenience and it puts a lot of pressure on the city of Davos as a host but so far we have not seen any drop-off in registrations," Monck said.

With the weather forecast to clear on Tuesday, organizers are hoping transport will start to operate more smoothly and will be running without a hitch by the time US President Donald Trump arrives on Friday to give the closing address.

However, so much snow has built up on the slopes surrounding Davos that avalanches remain a danger.

A bulletin from the SLF Institute for Snow and Avalanche Research in Davos showed a broad band of the mountainous country under Level 5 avalanche danger, the highest on a 1-5 scale.

"Fresh snow and snow drift accumulations are prone to triggering (avalanches). Until late in the night a large number of natural avalanches are to be expected," it said.

Snow slides could be deep and large, it added, posing danger to exposed settlements and transit routes.