US special envoy to Ukraine resigns following release of whistleblower report

US special envoy to Ukraine, Kurt Volker, resigned on Friday (local time), a day after the whistleblower report in connection with Trump-Ukraine scandal was made public.

Quoting sources familiar with the matter, CNN reported that Volker was named in the White House report.

Volker has become a key player in the unfolding scandal surrounding the whistleblower complaint concerning Trump's July 25 phone call with Ukraine President Volodymyr Zelensky, in which Trump had pressured Ukraine to investigate former Vice President Joe Biden and his son, Hunter.

CNN previously reported that before the phone call was made, Zelensky had joked with Volker about Rudy Giuliani, Trump's personal attorney who is also a key player in the scandal.

Volker later set up a meeting between Giuliani, who had been interested in getting Ukraine to investigate Joe and Hunter Biden, and a Zelensky adviser in an effort to get the Biden matter out of official talks.

There is no evidence of wrongdoing by either Joe or Hunter Biden.

The news of Volker's resignation comes just hours after the House Foreign Affairs Committee announced they would hold a deposition for him next week.

"We still expect to hear everything he knows about this scandal," said a congressional aide familiar with the deposition plans. But it's unclear if he will still speak with the committee on the planned date.

Volker was appointed by former secretary of state, Rex Tillerson.

Volker got along with Secretary of State Mike Pompeo but remained very much associated with the late Arizona Senator John McCain, "which is not a winning character trait for Trump" explained another source close to Volker. He never became an insider in the Trump administration, but due to his contacts with Giuliani he had an increasingly complicated role.