The Democratic-controlled House will examine whether President Trump abused his powers and sought Ukraine's help to smear former vice president Joe Biden, a 2020 Democratic front runner, House Speaker Nancy Pelosi said.

This combination of pictures created on September 24, 2019 shows US President Donald Trump (R) at UN Headquarters in New York and US Speaker of the House Nancy Pelosi, Democrat of California, in Washington, DC, both photographed on September 24, 2019.
This combination of pictures created on September 24, 2019 shows US President Donald Trump (R) at UN Headquarters in New York and US Speaker of the House Nancy Pelosi, Democrat of California, in Washington, DC, both photographed on September 24, 2019. (AFP)

US House Speaker Nancy Pelosi said on Tuesday the House of Representatives will launch a formal inquiry into whether President Donald Trump should be impeached, declaring that no one is above the law.

The Democratic-controlled House will examine whether Trump sought Ukraine's help to smear former Vice President Joe Biden, the front-runner for the 2020 Democratic presidential nomination, Pelosi said.

"Therefore today I'm announcing the House of Representatives is moving forward with an official impeachment inquiry," she said.

"The president must be held accountable. No one is above the law," Pelosi said.

Trump reacted to the announcement with his usual scorn. 

The burgeoning scandal centres on Trump's reported attempt to pressure the new president of Ukraine to open a corruption investigation into Biden and his son Hunter. Trump, however, denies the claim and has vowed to release transcripts of his phone conversation with the Ukrainian leader.

Triggering the confrontation is an as yet secret whistleblower complaint centred on Trump's phone call July 25 with Ukrainian President Volodymyr Zelenskiy.

Ukrainian President Volodymyr Zelenskiy listens during a meeting with the lawmakers in Kiev, Ukraine, Tuesday, May 21, 2019.
Ukrainian President Volodymyr Zelenskiy listens during a meeting with the lawmakers in Kiev, Ukraine, Tuesday, May 21, 2019. (AP)

Trump admits he froze Ukraine aid

News reports late Monday said the White House froze military aid to Ukraine just days before Trump urged Zelenskiy to investigate the Bidens.

Trump confirmed Tuesday that he had withheld the aid, but insisted it related to pressuring European countries to put up more to support Kiev.

Yet the White House continued to block the release of the whistleblower complaint and a transcript of the call.

"I think it's ridiculous, it's a witch hunt," Trump said in New York before addressing the United Nations General Assembly.

"I'm leading in the polls. They have no idea how they stop me. The only way that they can try is through impeachment."

Trump later said he will release the "fully declassified" transcript of the controversial call with Zelenskiy.

"I am currently at the United Nations representing our country, but have authorised the release tomorrow of the complete, fully declassified and unredacted transcript of my phone conversation with President Zelensky of Ukraine," Trump tweeted.

"You will see it was a very friendly and totally appropriate call," wrote Trump, who is accused of pressuring Zelensky to investigate his White House rival Joe Biden and his son.

"No pressure and, unlike Joe Biden and his son, NO quid pro quo!"

'Flagrant disregard for law'

Calls for impeachment intensified after the latest disclosures, which come on top of multiple congressional investigations into Trump's alleged attempts to collude with Russia, obstruction of justice, and profiteering from his office.

After seven moderate Democrats declared themselves in support of a full-blown impeachment probe late Monday, analysts counted a total of around 150 of the party's 235 House members in support.

"The president of the United States may have used his position to pressure a foreign country into investigating a political opponent, and he sought to use US taxpayer dollars as leverage to do it," the seven, including Afghanistan and Iraq wars veteran Jason Crow and ex-CIA agent Abigail Spanberger, wrote in the Washington Post.

"This flagrant disregard for the law cannot stand."

Speaker of the House Nancy Pelosi (D-CA) and Vice President Mike Pence react as female Democratic members of the House of Representatives applaud President Donald Trump after he said that there are now more women in Congress than ever during his second State of the Union address to a joint session of the US Congress in the House Chamber of the U.S. Capitol on Capitol Hill in Washington, US February 5, 2019.
Speaker of the House Nancy Pelosi (D-CA) and Vice President Mike Pence react as female Democratic members of the House of Representatives applaud President Donald Trump after he said that there are now more women in Congress than ever during his second State of the Union address to a joint session of the US Congress in the House Chamber of the U.S. Capitol on Capitol Hill in Washington, US February 5, 2019. (Reuters)

Possibly 'no choice' but impeachment - Pelosi

That increased pressure on Pelosi, who as leader of the Democrats in the House of Representatives sets their legislative and political agenda.

The wily San Francisco representative has so far resisted impeachment, preferring to focus on beating Trump and Congressional Republicans in the November 2020 election.

Pelosi, 79, takes credit for retaking a resounding Democratic majority in the House in the 2018 congressional elections and believes a similarly focused effort can regain control of the Senate and White House next year.

In addition, polls suggest American voters have no stomach for an impeachment investigation and Democrats recognize that even if it results in impeachment by the House, the Republican-controlled Senate would have the final say.

But Trump's latest scandal and refusal to bow to demands from Congress for information could leave Democrats "no choice" but to pursue impeachment, Pelosi said Monday.

Democratic presidential candidate former Vice President Joe Biden speaks during a town hall meeting at the Indian Creek Nature Preserve in Cedar Rapids, Iowa. September 20, 2019.
Democratic presidential candidate former Vice President Joe Biden speaks during a town hall meeting at the Indian Creek Nature Preserve in Cedar Rapids, Iowa. September 20, 2019. (Charlie Neibergall / AP)
Source: TRTWorld and agencies