US President Donald Trump attacked former US ambassador to Ukraine Mary Jovanovich as she testified on Friday in the US House of Representatives as part of an inquiry into his accountability.
"Everywhere Mary Jovanovic went, things turned. She started in Somalia, and see how it ended up there," Trump tweeted.
He added: "The US president has an absolute right to appoint ambassadors," stressing that he has "a strong foreign policy and very strong, very different from the policies of previous administrations."
The Democrat, who is leading the investigation, cut the course of testimony to tell Jovanovic that the US president had just launched an attack against it.
Jovanovic was surprised by Trump's words. "I don't think I had that ability, either in Mogadishu, Somalia, or anywhere else," she said. "This is very scary."
Jovanovic was quickly summoned from Kiev to Washington in May after being defamed by Trump's personal lawyer, Rudy Giuliani.
Jovanovic vowed not to be "politically biased" and asserted that she had served the United States for 33 years.
On the second day of public television sessions on accountability, Mary Jovanovic explained how she was fighting corruption in Ukraine and how the Trump administration suddenly returned to Washington earlier this year.
The US House of Representatives session yesterday followed a long hearing on the Ukrainian issue, which began last September, and was conducted secretly to isolate Trump.
A US intelligence official revealed a phone call on July 25 between the US president and his Ukrainian counterpart.
The issue prompted Democrats, who control the House of Representatives, to open an investigation on Sept. 25 on suspicion of abuse of power by the president by asking for help from a foreign country to intervene in the election, in an attempt to discredit his political opponent, Joe Biden.
The speaker of the US House of Representatives, Nancy Pelosi, earlier, that investigations into the removal of the US president will focus on his behavior towards Ukraine.