Fresh calls for the impeachment of President Donald Trump will move a step closer on Tuesday as House Democrats head into a closed-door meeting with Speaker Nancy Pelosi at 4:00 p.m.

Democrats themselves remained divided on moving forward with an effort to impeach Trump. Pelosi has resisted calls for impeachment and is sticking with her position that Congress must not start formal proceedings unless the American public demands it.

Trump has been defiant, openly acknowledging that during a July discussion with Ukraine President Volodymyr Zelensky, he raised the subject of whether former Vice President Joe Biden was at the root of any corruption.

While he denies asking Zelensky to investigate the man who is now his angriest Democratic rival, he told reporters Monday at the United Nations that 'it would probably, possibly have been O.K. if I did.'

'But I didn't,' he said, his dander up in a conflict posture. 'I didn't put any pressure on them whatsoever.'

He also ripped the impeachment effort in comments at the UN Tuesday: 'I think it's ridiculous. It's a witch hunt. I'm leading in the polls. They have no idea how they stop me. The only way they can try is through impeachment.'

Trump also insists he didn't threaten to punish Ukraine by holding up military aid money if Zelensky failed to investigate Biden. But he hasn't explained the most recent revelation – that he pressed pause on hundreds of millions of dollars just one week before the summer phone call.

House Speaker Nancy Pelosi has resisted calls for impeachment and is sticking with her position that Congress must not start formal proceedings unless the public demands it

Allegations that President Donald Trump pressured Ukraine's leader to investigate the family of political rival Joe Biden at the same time he was withholding millions in aid from the Eastern European nation are raising alarms in Congress

Pelosi weights resolution to condemn Trump's Ukraine action

Pelosi and her leadership team on the various oversight committees are considering bringing forward a resolution that will put the House on record on this matter, according to a Democratic leadership aide unauthorized to discuss the private talks. The aide was granted anonymity.

The speaker said Sunday that unless the administration provides more information to Congress by the scheduled Thursday hearing at the intelligence committee, its officials 'will be entering a grave new chapter of lawlessness which will take us into a whole new stage of investigation.'

'I think we're reaching a tipping point both within our base and within our caucus,' Rep. Gerry Connolly, a Democrat on the House Oversight and Foreign Affairs committees, told CNN on Monday.

'This weekend, all I hear at home is when are Democrats going to get tough?' Connolly said. 'We are looking weak.'

Allegations that President Donald Trump pressured Ukraine's leader to investigate the family of political rival Joe Biden at the same time he was withheld millions in aid from the Eastern European nation are raising alarms in Congress and pushing a wave of House Democrats toward impeachment proceedings.

Late Monday, an influential group of freshmen Democrats who served in the military and national security before winning office said Trump's actions cut to the core of the country's defenses. Their views, as centrist lawmakers from previously Republican-held districts where Trump has been popular, hold sway with party leadership.

Trump acknowledged bringing up Joe Biden and Hunter Biden during a call with the Ukrainian president

At issue is a summer phone call with Ukrainian President Voldymyr Zelenskiy, in which Trump is said to have pushed for investigations into Biden. In the days before that call, Trump ordered the aid to Ukraine frozen, according to reports in The Washington Post and The New York Times.

Trump has insisted he did nothing wrong and has denied that any requests for help in procuring damaging information about Biden were tied to the aid freeze.

Democrats, and some Republicans, urged the White House to be open about his actions, which are the center of a whistleblower complaint. But with no new information from the administration forthcoming, more than a dozen Democrats, including some in House leadership, added their names to those calling for impeachment proceedings.

The sudden rush of activity shows the extent to which Trump's call to the foreign leader, and his subsequent comments about the conversation, are raising further questions about whether the president improperly used his office to pressure another country as a way of helping his own reelection prospects.

'These allegations are stunning, both in the national security threat they pose and the potential corruption they represent,' wrote the seven freshmen, who include a former fighter pilot, soldiers, officers and intelligence analysts.

Meanwhile, Senate Democratic Leader Chuck Schumer of New York called on Republican Majority Leader Mitch McConnell to investigate the whistleblower's complaint

'We do not arrive at this conclusion lightly,' the lawmakers wrote in a Washington Post op-ed. 'These new allegations are a threat to all we have sworn to protect. We must preserve the checks and balances envisioned by the Founders and restore the trust of the American people in our government. And that is what we intend to do.'

Congress demanding whistleblower complaint

Congress on Monday pressed for full disclosure of a whistleblower's complaint about Trump and pushed the White House to release a transcript of Trump's call with the Ukraine president.

The president has acknowledged the phone call. On Monday, he said he didn't want to give money to Ukraine - if there were corruption issues.

'It's very important to talk about corruption,' Trump told reporters as he opened meetings at the United Nations. 'If you don't talk about corruption, why would you give money to a country that you think is, is corrupt?'

Later Monday, Trump denied telling the Ukraine president that his country would only get U.S. aid if it investigated Biden's son. 'I didn't do it,' he said.

President Trump said Monday he may, or may not, release details or a transcript of the call but has stressed that foreign leaders should feel free to speak frankly with an American president without fear that the details of their conversations will later be disclosed

Trump has sought, without evidence, to implicate Biden and his son Hunter in the kind of corruption that has long plagued Ukraine. Hunter Biden served on the board of a Ukrainian gas company at the same time his father was leading the Obama administration's diplomatic dealings with Kyiv. Though the timing raised concerns among anti-corruption advocates, there has been no evidence of wrongdoing by either the former vice president or his son.

The matter is under new scrutiny following the whistleblower's mid-August complaint, which followed Trump's July 25 call with Ukraine President Volodymyr Zelenskiy. The person who filed the complaint did not have firsthand knowledge of the call, according to a person familiar with the matter.

Lawmakers are demanding details of the complaint, but the acting director of national intelligence, Joseph Maguire, has refused to share that information, citing presidential privilege. He is set to testify Thursday before the House.

'Let's see the transcript,' said Sen. Mitt Romney, R-Utah, about Trump's call with the Ukraine president.

The chairmen of the House intelligence, Foreign Affairs and Oversight and Government Reform committees are threatening to subpoena Secretary of State Mike Pompeo if he does not produce information about whether Trump and his lawyer, Rudy Giuliani, inappropriately tried to influence the Ukraine government for political gain.

Meanwhile, Senate Democratic Leader Chuck Schumer of New York called on Republican Majority Leader Mitch McConnell to investigate the whistleblower's complaint. In a letter to McConnell, he said that the Republicans' 'see no evil, hear no evil' attitude toward the president's actions 'is unacceptable and must change.'

Republican Sen. Marco Rubio of Florida doesn't think Trump's actions are grounds for impeachment, but said he wouldn't have called a foreign leader to discuss a rival.

'I don't think he should have raised the topic of Joe Biden with the Ukraine president,' Rubio said.

Senate Majority Leader Mitch McConnell said Monday the matter is best left behind closed doors in the classified setting of the intelligence committee, though he did push into the spotlight his own role in securing the Ukraine aid.

McConnell said he had been 'personally pressuring' the Trump administration this summer in calls to Pompeo and Secretary of Defense Mark Esper to release the U.S. aid money.

House Democratic calls for impeachment grow

New revelations about President Donald Trump's call with the president of Ukraine have prompted a steady stream of House Democrats to come out for impeachment in some form.

The latest lawmaker to jump on board the impeachment effort is New York Democratic Rep. Anthony Delgado, who defeated a Republican incumbent in a district that Trump carried in Schenectady.

'The first responsibility of the President of the United States is to keep our country safe, but it has become clear that our president has placed his personal interests above the national security of our nation. I believe articles of impeachment are warranted,' Delgado said in a statement Monday.

'The President has admitted to soliciting the Ukrainian president to investigate a political rival,' said Delgado, 'In doing so, the President used the power of the presidency to pressure a foreign government to help him win an election. This, by itself, is an impeachable offense. And yet, even more troubling is the fact that prior to this conversation, the President instructed his administration to withhold military aid that Ukraine needed to fend off Russian aggression,' he continued. 'Having taken an oath of office before God and my fellow citizens to support and defend the Constitution of the United States, I can only conclude that Congress move forward with articles of impeachment.'

His support from the effort came hours after Connecticut Rep. Rosa DeLauro, a longtime party stalwart and ally of Pelosi, saying an impeachment inquiry 'may be the only recourse.'

“President Trump is continuing to test the bounds of our laws and our Constitution. No President of the United States should use their position to insist that a foreign leader investigate one of his political opponents—let alone withhold Congressionally appropriated foreign aid for such purposes,' DeLauro said in a statement. 'This represents a new chapter in Trump’s egregious conduct, one that is based on actively interfering with the 2020 election rather than his past misconduct around the 2016 election. If these findings are true, they are a reckless abuse of power that put his own interests ahead of those of the American people,' she said.

She said the whistle-blower who brought the compliant must be able to come forward without retribution, and that the House Intelligence panel must get unfettered access to the whistle-blower's report.

'An impeachment inquiry may be the only recourse Congress has if the President is enlisting foreign assistance in the 2020 election. Congress must meet this pivotal moment in our nation’s history with decisive action,' she said.

More than a dozen House Democrats came out for some form of impeachment proceeding since the Ukraine story reemerged last week.

Among them are Rep. Dean Phillips and Angie Craig of Minnesota.

On Monday night, a group of seven freshman Democrats representing tough political terrain, all of them veterans or having served in intelligence or defense, got behind impeachment.

They represent the type of seats Pelosi is seeking to protect with a more cautious approach on impeachment.

'This flagrant disregard for the law cannot stand. To uphold and defend our Constitution, Congress must determine whether the president was indeed willing to use his power and withhold security assistance funds to persuade a foreign country to assist him in an upcoming election,' they wrote.

'If these allegations are true, we believe these actions represent an impeachable offense,' they said, adding that they encourage Congress to use its powers of 'inherent contempt' to investigate.

They writers were: Reps. Gil Cisneros of California, Jason Crow of Colorado, Chrissy Houlahan of Pennsylvania, Elaine Luria of Virginia, Mikie Sherrill of New Jersey, Elissa Slotkin of Michigan and Abigail Spanberger of Virginia.

Trump may or may not release transcript

Trump said Monday he may, or may not, release details or a transcript of the call but has stressed that foreign leaders should feel free to speak frankly with an American president without fear that the details of their conversations will later be disclosed.

Hunter Biden was hired by the Ukrainian gas company Burisma Holdings in April 2014, two months after Ukraine's Russia-friendly former president was ousted by protesters and as Biden's father was heavily involved in U.S. efforts to support the new pro-Western government. The move immediately raised concerns that the Ukrainian firm, whose owner was a political ally of the ousted president, was seeking to gain influence with the Obama administration.

Trump and Zelenskiy plan to meet on the sidelines of the U.N. General Assembly this week.