"After more than a year of service at the National Security Council, Mr. Morrison has decided to pursue other opportunities — and has been considering doing so for some time. We wish him well,” a senior administration official said Wednesday in a statement obtained by Politico.
Morrison was set to testify before the House impeachment committees on Thursday regarding US President Donald Trump's July 25 phone call with Ukrainian President Volodymyr Zelenskyy.
House impeachment investigators are investigating whether Trump threatened to withhold almost $400 million in military aid to Ukraine if the country did not agree to look into former Vice President Joe Biden son's activities in relation to a Ukrainian gas company. Morrison became involved in the scandal after William Taylor, Trump's top envoy to Ukraine, testified earlier this month that Morrison heard an incriminating conversation between Gordon Sondland, the ambassador to the European Union and a senior Ukrainian official. During the conversation, Sondland allegedly said that military aid to Ukraine depended on whether the country would succumb to Trump's demand.
The formal inquiry began on September 24, following publication of a transcript of the Trump-Zelenskyy phone call.
In the coming days, three House committees are expected to question National Security Advisor John Bolton's former colleagues – the ex-national security adviser’s deputy, Charles Kupperman and a current National Security Council staffers - Alexander Vindman.