The FBI last month requested an interview with the whistleblower whose complaint fueled the impeachment inquiry into President Donald Trump and Ukraine, a person familiar with the situation said Wednesday. An agent from the FBI’s Washington field office reached out to the whistleblower’s lawyers last month to seek an interview about the substance of the complaint, according to this person, who insisted on anonymity to discuss the request with The Associated Press. The person said it was clear from the FBI that the whistleblower was not regarded as the target of any investigation but rather a potential witness. It was...