A top national security aide to Vice President Mike Pence told House impeachment investigators that President Donald Trump’s efforts to pressure Ukraine to investigate his political opponents were “unusual and inappropriate,” and “shed some light on possible other motivations” for the president’s order to freeze military aid to the U.S. ally.

Jennifer Williams, who serves as Pence’s special adviser for Europe and Russia, told investigators in early November that she took notes while she listened in on Trump’s July 25 phone call with Ukrainian President Volodymyr Zelensky from the White House Situation Room, adding that she viewed Trump’s requests for investigations as politically motivated.

“I found the specific references to be — to be more specific to the president in nature, to his personal political agenda, as opposed to a broader … foreign policy objective of the United States,” Williams said, according to a transcript of her closed-door deposition released Saturday.