Washington (AFP) - US President Donald Trump on Monday swatted away mounting pressure from Democrats demanding his impeachment, as he rejected accusations that he sought to extort Ukraine into revealing dirt on his political rival Joe Biden.
Trump said he is "not at all" worried about an impeachment threat and tried to make the controversy about Biden, accusing the former vice president, without evidence, of engaging in corruption in Ukraine.
Democrats have fumed as Trump's administration has blocked Congress from obtaining a whistleblower's secret complaint allegedly detailing the president's actions, and they ramped up their demands for the document that sparked the latest crisis.
The complaint reportedly centers on Trump's July phone call with Ukrainian counterpart Volodymyr Zelensky, and a possible attempt to coerce him into digging up damning information about Biden's son's business dealings in Ukraine.
Trump has acknowledged that the conversation addressed alleged corruption involving Biden and son Hunter.
On Monday, he leveled bald attacks on the Democratic frontrunner in the 2020 White House race.
"Joe Biden and his son are corrupt," he said, providing few details other than to say Hunter Biden, who once served on a Ukrainian natural gas company's board, "took money from Ukraine."
He also insisted that, in his call with the Ukrainians, "I put no pressure on them whatsoever," and "I did not make a statement that you have to do this or I won't give you aid."
Trump also signaled he might release a transcript of the "very honorable call" with Zelensky.
Biden fired back on Twitter: "So release the transcript of the call then."
To date, there has been no evidence of illegal conduct in Ukraine by the Bidens.
House Speaker Nancy Pelosi, who so far has hesitated to call for impeachment, signaled that her position could change.
If the administration does not produce the whistleblower complaint, "they will be entering a grave new chapter of lawlessness which will take us into a whole new stage of investigation," she said Sunday.
- 'An impeachable offense' -
Several Democrats argue that Trump's call for Ukraine to investigate Biden -- and what they suspect was a threat to condition $250 million in aid to Ukraine on the country doing so -- is impeachable conduct.
That view may be pushing House leaders toward a tipping point for launching removal proceedings.
"Of course it's an impeachable offense," congressman Jim Himes told CNN.
"I can't tell you that the House will move into impeachment mode right away, but this really ups the ante."
Three liberal House Democrats joined an impeachment protest on Capitol Hill, warning that voters could turn on Congress if it declines to bring a renegade president to justice.
"We are at the crossroads of accountability. Either we will hold the president accountable, or we will be held accountable," congressman Al Green said.
"It is time for the Congress to do its job and start the impeachment process, not an inquiry."
With pressure building, a handful of Republicans in the US Senate -- which would put Trump on trial should the House impeach him -- have indicated they want the president to be more transparent.
"I would just urge the president -- you know, he's talking openly about the conversation -- to release as much as possible," Trump loyalist Senator Lindsey Graham told the Hugh Hewitt radio show.
Senator Mitt Romney, the 2012 Republican presidential nominee, went further, warning that evidence of Trump asking Ukraine's president to investigate Biden "would be troubling in the extreme."
But most congressional Republicans have either defended the president or remained silent.
All eyes will be on Washington Thursday, when the administration official who blocked congressional review of the whistleblower document, acting Director of National Intelligence Joseph Maguire, testifies publicly before a House panel.
Launching impeachment proceedings could be politically risky ahead of an election, especially given the high hurdle of convicting the president in the Republican-led Senate.
Of the 235 House Democrats, 137 of them, plus Republican-turned-independent Justin Amash, support launching an impeachment inquiry, according to CNN's count.
Democratic leaders have hesitated to pull the impeachment trigger, but House Intelligence Committee chairman Adam Schiff said his own reservations about impeachment were fading and that the House may have "crossed the Rubicon" in light of Trump's Ukraine call.