The outlook among CEOs of large US companies fell for the first time since President Donald Trump took office in the second quarter amid rising trade-war worries, said a survey released Tuesday.

Confidence among chief executives remains "strong" and well above historical average but an overwhelming number of corporate leaders expressed concern about the administration's trade policies, according to the Business Roundtable.

A whopping 89 percent of CEOs described lower US economic growth as a "moderate" (58 percent) or "serious risk" (31 percent), said the survey of the roundtable, which represents U.S. business giants.

"We continue to see strong CEO plans in the second quarter of 2018 but uncertainties about trade policy are a growing weight on economic progress -- especially amid escalating trade tensions," said Business Roundtable president Josh Bolton.

The overall CEO Economic Outlook index fell to 111.1 in the second quarter from 118.6 in the first quarter, the first drop in nearly two years, but well above the historical average of 81.2.

The report, based on a survey of 132 CEOs over a two-week period in May, showed drops in all major components, with the outlook for sales, capital spending and hiring all diminished compared with the prior report.

For example, 61 percent of companies expect an increase in capital sales over the next six months, down from the 68 percent in the first-quarter survey.

The percentage of companies expecting "no change" rose five points to 35 percent and those seeing a decline doubled to a still-small four percent.

On trade specifically, overwhelming majorities characterized the chance of higher costs and foreign trade retaliation as a moderate or serious risk for U.S. companies.