President Donald Trump has said he will "probably" release a transcript detailing a second phone call he had with his counterpart in the Ukraine next week.
It comes amid an impeachment inquiry into the US leader, which he branded a "witch hunt".
Mr Trump said the details of another call he had with the Ukraine's president Volodymyr Zelensky would likely be published on Tuesday.
In September, Mr Trump released a summary of a July 25 call with the Ukrainian president, after a whistle blower claimed he urged Mr Zelensky to look for potentially damaging information on Democrat Joe Biden.
Detailing plans to release a second call, he said: "We'll probably give it to you on Tuesday.
"They asked for it and I gladly give it, there's never been a President who's been so transparent.
"I actually had two calls with the President of the Ukraine... you'll tell me if there's anything wrong with it."
It comes as Republicans on Saturday asked that former Vice President Joe Biden's son and the whistleblower whose complaint triggered the impeachment inquiry be called to testify in public hearings that begin next week.
Democrats who control the US House of Representatives, however, likely will reject appearances by Mr Biden and the unidentified whistleblower in the hearings, which are due to open on Wednesday.
