The timing of the request suggests it could also be related to an intelligence community whistleblower complaint about President Trump's July phone call with the president of Ukraine, during which he asked the foreign leader to investigate Joe Biden, the former vice president and his possible 2020 general election opponent. A congressional aide described the request as "highly unusual and cryptically worded."

Linick's ask also follows Secretary of State Mike Pompeo's Tuesday response to a subpoena for Ukraine documents, in which he accused House Democrats of attempting to "bully" State Department employees.