U.S. trade policy has risen to the top of the list of "biggest external risks" facing the members of the CNBC Global CFO Council.

More than a quarter (27.3 percent) of council members responding to a quarterly poll say U.S. trade policy is now the biggest risk their company faces. That's up from 11.6 percent in the fourth quarter of 2017, outranking other threats that have recently ranked high among business concerns, including "threat of cyberattack" and "consumer demand."

The CNBC Global CFO Council represents some of the largest public and private companies in the world, collectively managing more than $4.5 trillion in market capitalization across a wide variety of sectors.

The survey was conducted after President Donald Trump signed a pair of proclamations that impose tariffs on imported steel and aluminum, but before the announcement on Thursday that the United States will seek trade penalties of up to $60 billion against China for intellectual property theft.