Updated at 4:35 p.m. ET
President Trump held a press conference Wednesday with visiting Finnish President Sauli Niinistö, as the impeachment probe into Trump's conduct intensifies.
Trump faced questions about the House inquiry that was sparked by a whistleblower complaint that accuses Trump of pressuring Ukraine's president to investigate former Vice President Joe Biden and his son Hunter.
Trump has continued to defend the call, saying he did nothing improper. Earlier Wednesday, he blasted Democrats on Twitter for "wasting everyone's time and energy."
House Democrats have threatened the White House with a subpoena for documents related to the call if it does not comply with their requests.
Earlier on Wednesday, Secretary of State Mike Pompeo acknowledged that he was listening to the phone call with Ukraine's president after evading earlier questions about his knowledge of the conversation.