Several House committees were currently investigating whether Trump delayed some $250 million in congressionally approved aid to Ukraine as he allegedly pressured Zelensky to look into Biden's activities in that nation, reports Efe news.
The head of the Democratic minority in the upper chamber, Chuck Schumer, on Monday sent a letter to Republican Senate Majority Leader Mitch McConnell in which he demanded that the conservatives issue a subpoena to the Trump administration to force it to turn over the so-called whistleblower complaint to Congress "as required by law".
The Wall Street Journal reported on September 20 that Trump had repeatedly asked Zelensky in a telephone call to investigate Hunter Biden, the former Vice President's son.
According to the paper, citing persons with knowledge of the matter, during the call Trump asked Zelensky up to eight times to work with his personal attorney, Rudy Giuliani, to investigate Hunter Biden's business dealings and contacts in Ukraine.
Trump spoke with Zelensky two weeks before a US intelligence official filed an internal whistleblower complaint on August 12, a move that alerted Congress to the matter.
In his letter, Schumer said that "the Republican-led Senate has remained silent and submissive, shying away from this institution's constitutional obligation to conduct oversight. The Republican Senate's 'see no evil, hear no evil' attitude (regarding) such a serious national security concern is unacceptable and must change".
On September 21, Trump said in a tweet that "now the fake news media says I 'pressured the Ukrainian President at least eight times during my telephone call with him'. This supposedly comes from a so-called 'whistleblower' who they say doesn't even have a first hand account of what was said. More Democrat/Crooked Media."
In another tweet, Trump said: "Breaking News: The Ukrainian Ggovernment just said they weren't pressured at all during the 'nice' call. Sleepy Joe Biden, on the other hand, forced a tough prosecutor out from investigating his son's company by threat of not giving big dollars to Ukraine. That's the real story."
Trump has claimed Joe Biden demanded the 2014 removal of a notoriously corrupt Ukrainian prosecutor to hinder the probe into a Ukrainian gas company on which he was a board member at the time. Ukrainian authorities, however, have cleared him of any wrongdoing.
The President said that his call with Zelensky was perfectly routine and that he did not say or do anything that would be improper or unlawful.
However, on September 22, he then admitted that he had spoken about Joe Biden with Zelensky, telling reporters at the White House that "the conversation I had was largely congratulatory, with largely corruption, all of the corruption taking place and largely the fact that we don't want our people like Vice President Biden and his son creating to the corruption already in the Ukraine".
On Monday morning in New York, Trump responded to a reporter's question about whether he was taking seriously the possibility that he could be impeached over the whistleblower matter, saying: "Not at all seriously... We had a perfect phone call with the president of Ukraine. Everybody knows it. It's just a Democrat witch hunt."
( With inputs from IANS )