U.S. Secretary of the Treasury Steve Mnuchin hit Capitol Hill on Thursday to face a grilling on trade, tariffs and NAFTA from the House Financial Services Committee. Mnuchin attempted to quell growing uncertainty within Congress as President Trump ratchets up a trade war with China. It if the trade war's toll on the economy hasn't been seen yet, recent data from a CFO survey conducted by CNBC suggests the economic hit is coming. And Congress took notice of that data during Mnuchin's hearing.

"CNBC does a survey of CFOs of major U.S. companies and 65 percent have reported that they fear U.S. trade policy will negatively impact their firms over the next six months. How does the administration think about business uncertainty as it calculates its trade policy?" Republican congressman Jeb Hensarling of Texas, who chairs the House Financial Services Committee, asked Mnuchin.

"I can assure you that the President is very much focused on economic growth and I can also assure you that I am motoring the situation very carefully," Mnuchin told Hensarling. "We have not yet seen any negative impact."

Trade uncertainty has risen to be the biggest risk for corporations, according to the latest CNBC Global CFO Council quarterly survey. To that point, 35 percent of global CFOs say U.S. trade policy is the biggest external risk their company faces, up from 27 percent in Q1 and tripling from the 11.6 percent who cited trade policy in the fourth quarter of 2017.