Joseph Maguire, the acting US Director of National Intelligence, has told the House Intelligence Committee a whistleblower "did the right thing" by highlighting a memorandum regarding a telephone conversation between US President Donald Trump and Ukrainian President Volodymyr Zelenskiy.
Maguire testified to the committee on the whistleblower report, released by a congressional panel on Thursday, which claimed Trump used his office to solicit Ukraine's interference in the 2020 election to advance his personal political interests, risking US national security.
You can watch the event back in the above video player.
Maguire used his opening statement to insist he was "not political" and defended not immediately handing the report over to Congress because he believed it to be "prudent" to find out at the White House whether the report was "protected by executive privilege".
Pushed by the chairman of the Democratic-led House intelligence committee, Adam Schiff, Maguire eventually conceded: "I think the whistleblower did the right thing".
Asked whether the whistleblower will be protected by law and be able to testify freely once given security clearance, Maguire said "yes".
The committee released a declassified version of the report made by the whistleblower, which triggered weeks of controversy and prompted House Speaker Nancy Pelosi to launch a formal impeachment inquiry into the Republican president.
Democrats have accused the US president of asking Zelensky to look into corruption involving Trump's possible 2020 election rival, Joe Biden.
They say Trump pressed Ukrainian President Volodymyr Zelenskiy to investigate Biden, citing a summary of a July telephone call released by the Trump administration on Wednesday.
Trump has denied wrongdoing and accused Democrats of trying to destroy him politically.
Maguire refused for weeks to share the whistleblower report with Congress.
A federal law required that the report be sent to lawmakers after an inspector general determined that it was urgent and credible.
The US has been giving military aid to Ukraine since Russia's annexation of Crimea in 2014. The $391.5 million in aid, at issue in the current controversy, was approved by Congress to help Ukraine deal with an insurgency by Russian-backed separatists in the eastern part of the country.
The call occurred after Trump had ordered a freeze of nearly $400 million in American aid to Ukraine, which the administration only later released.