Global auditing firm KPMG has highlighted geopolitical risk as the main issue occupying the minds of attendees at the World Economic Forum (WEF) in Davos, Switzerland.

Bill Thomas, chairman of KPMG International, told CNBC on Monday that a survey of 1,300 chief executives had showed that geopolitical risk has risen right to the top of leaders’ concerns and was encouraging executives to seek answers.

“It is all about uncertainty. Businesses today, if they know what the rules of the game are, then they can respond,” he said.

“But the geopolitical risks that we have are so uncertain, that’s why we are seeing record numbers here at the World Economic Forum.”

Thomas added that last year’s speech by Chinese President’s Xi showed how influential Davos can be in shaping people’s thinking.

KPMG revenues grew to a record $26.4 billion for the 2017 fiscal year. The company said growth is being driven by investments in technology, alliances and developing new services.

The company said in December that its workforce was around 200,000 employees.

Thomas became chairman of KPMG International in October last year and will lead the KPMG network of professional services for a four-year term.