Trump denies pressuring Ukraine to investigate Biden

U.S. President DonaldTrump on Monday denied trying to coerce Ukraine intoinvestigating his Democratic political rival Joe Biden, butwavered about whether he would release a transcript of a phonecall that some Democrats say is grounds for his impeachment.

Trump's statements come after he confirmed on Sunday that he did raise the subject ofJoe Biden and his son, Hunter, in the July 25call with Ukraine's President Volodymyr Zelensky.

That callhas been at the centre of an escalating battle in Washington since Friday, when news outlets reported Trump repeatedly asked the Ukrainian leader to investigate whether Biden, the Democratic front-runner to take on Trump in next year's election, misused his position when he was vice-president.

Democrats, and some Republicans, urged the White House to be forthcoming amid the reports of coercion, which would have occurred at the same time the administration was withholding $250 million in aid to the Eastern European nation.

Trump has denied doing anything improper,stating he didn't want to give money to Ukraineif there were corruption issues. His allies, including Secretary of State Mike Pompeo and his personal attorney, Rudy Giuliani, have defended the president's phone call, which, according to news reports, was the subject of a complaint made by an as-yet-unnamed whistleblower.

If an investigation shows that Trump pressured Ukraine to investigate Biden, the U.S. Congress may have no choice but to pursue impeachment, Democratic House intelligence committee chairman Adam Schiff said on Sunday.

"If the president is essentially withholding military aid at the same time that he is trying to browbeat a foreign leader to do something illicit, to provide dirt on his opponent during a presidential campaign, then that may be the only remedy that is co-equal to the evil that conduct represents," Schiff said.

U.S. Senate DemocraticLeader Chuck Schumer called on Senate Republicans Monday toissue a subpoena for thewhistleblower complaint and demand a transcript of Trump's July 25 call with Zelenskiy.

"It is the Senate's duty duty to take this nationalsecurity matter seriously and investigate now. SenateRepublicans have the sole power and the overwhelmingresponsibility to see that it does," Schumer said in remarks onthe Senate floor.

Schumer said he made his request for a Senate investigationin a letter to Senate Republican leader Mitch McConnell.

More than half the House Democrats have said they support impeachment, and more are expected this week to publicly favour such an investigation, but others worry it is too politically divisive and would only alienate more centrist voters.Democratic House of Representatives Speaker Nancy Pelosi has alsoresisted calls to formally begin the process.

Trump gave a contradictory message about whether he wouldrelease a transcript of the call with the Ukrainian leader.

"I may do it because it was a very interesting call," Trumpsaid on Monday. "It was a very nice call. I hope you get to see it and Ihope you get to see it soon,"he said.

But he added:

"I don't think it's a great precedent to be releasing callswith foreign countries, heads of foreign countries. So I don'tthink it's a great precedent."

• WATCH: The National's story about Trump confirminghe discussed Biden in call with Ukrainian president

South Carolina Sen. Lindsey Graham, one of the president's closest allies, urged Trump on Monday to be "as transparent as possible" and predicted the White House transcript would be released.

"I think he did nothing wrong and he has nothing to hide," Graham said on talk show host Hugh Hewitt's radio program.

In a letter to colleagues later on Sunday, Pelosi warned the administration against keeping the details of the whistleblower complaint secret. The administration has so far resisted sharing the details of the complaint with lawmakers.

"If the administration persists in blocking this whistleblower from disclosing to Congress a serious possible breach of constitutional duties by the president, they will be entering a grave new chapter of lawlessness which will take us into a whole new stage of investigation," Pelosi wrote.

Trumpshrugged off talks of impeachment while speaking with reporters as he arrived at the UN General Assembly.

Asked how seriously he was taking the threats by Congress, Trump said, "Not at all seriously."

Trump is set to have a closed-door meeting with Pelosion Tuesday in regards to the complaint.

Romney voices concern

Sen. Mitt Romney, who has clashed with Trump in the past, sounded a rare note of concern among Trump's fellow Republicans, many of whom have remained silent, defended Trump or escalated their attacks on Biden in the days after the reports about the Trump-Zelensky call.

"If the president asked or pressured Ukraine's president to investigate his political rival, either directly or through his personal attorney, it would be troubling in the extreme," Romney, the 2012 Republican presidential nominee, said in a Twitter post.

Impeachment proceedings in Congress that begin in the Housecan lead to a president being removed from office, but Democrats would need the support of Republicans, who control the Senate.

Multiple news organizations reported on Friday that Trump repeatedly asked Zelensky to investigate whether Biden misused his position as vice-president under Democratic President Barack Obama to threaten to withhold U.S. aid unless a prosecutor who was looking into a gas company in which Biden's son was involved was fired.

Biden has confirmed he wanted the prosecutor fired but denies it was to help his son. Biden said the wider U.S. government, the European Union and other international institutions also wanted the prosecutor fired for his alleged failure to pursue major corruption cases.

Biden said on Saturday there should be an investigation into Trump's call, saying it "appears to be an overwhelming abuse of power." He said he never spoke to his son about Ukraine.