Shouts, glares and unprintable words: US Secretary of State Mike Pompeo lost his temper at a journalist after she questioned him on the administration's stance on Ukraine, a country at the heart of President Donald Trump's impeachment trial.

It began when Pompeo gave an early morning interview to NPR radio. Much of the discussion dealt with Iran, but journalist Mary Louise Kelly closed by asking Pompeo about Ukraine.

Democrats accuse Trump of abusing his office by pressuring Kiev to investigate his potential election challenger Joe Biden, a charge for which Trump has been impeached and is currently facing trial in the US Senate.

Pompeo, a close associate of Trump, has been accused of personally failing to defend Marie Yovanovitch, Washington's former ambassador to Ukraine who was abruptly called home last spring after being subjected to a smear campaign led by Rudy Giuliani, the president's personal lawyer.

"Do you owe Ambassador Marie Yovanovitch an apology?" Kelly asked Pompeo.

A tense exchange followed, wherein Pompeo said he had "defended every State Department official," while Kelly asked, in vain, when he had publicly defended Yovanovitch. "I've said all I'm going to say today. Thank you," Pompeo said finally, ending the interview.

But the story didn't end there, and Kelly related the rest in an NPR broadcast on Friday evening. She said she thanked the secretary, who did not reply but leaned in and glared at her before leaving the room.

A staffer then invited Kelly to Pompeo's private living room, without her recorder. There, Pompeo "was waiting and... he shouted at me for about same amount of time as the interview itself lasted," Kelly said.

"He was not happy to have been questioned about Ukraine," Kelly said, adding that the secretary asked her "do you think Americans care about Ukraine?" while saying swear words.

Pompeo then asked his advisers to bring out a map of the world without the countries labeled, to prove that Kelly knew where Ukraine was located. "I pointed to Ukraine. He put the map away," Kelly said. "People will hear about this," said Pompeo, who has publicly attacked journalists in the past.