CORRECTS FROM FLOOD DAMAGE TO DERECHO DAMAGE - Department of Homeland Security Acting Secretary Chad Wolf, right, listens as President Donald Trump speaks during a briefing on derecho damage and recovery efforts in Iowa, Tuesday, Aug. 18, 2020, in Cedar Rapids, Iowa.
The individual assistance request covers 27 counties.
Trump indicated Monday that he had signed the state's disaster aid request in full, but he had not approved the individual assistance, which makes up the largest portion of the $3.99 billion aid request.
FEMA spokesman Mike Cappannari said the assessment for the individual assistance portion of the declaration was underway.
The storm destroyed or damaged numerous outbuildings, barns, grain bins, homes, mobile homes, apartment buildings, trees and power poles, the weather service said.