President Donald Trump ratcheted up his defenses on Thursday, likening those who provided information to the whistleblower to spies, according to reports, and tweeting that "our country is at stake" on the day the complaint against the president was made public.

"THE DEMOCRATS ARE TRYING TO DESTROY THE REPUBLICAN PARTY AND ALL THAT IT STANDS FOR," Trump tweeted in all caps. "STICK TOGETHER, PLAY THEIR GAME, AND FIGHT HARD REPUBLICANS. OUR COUNTRY IS AT STAKE!"

Trump, according to multiple media outlets, told a private group at a midtown hotel Thursday morning that the people who gave information to the whistleblower were "close to a spy," and said the U.S. should "handle" them like it did "in the old days" — a veiled reference to execution.

The New York Times and The Los Angeles Times both reported on the comments. The Los Angeles Times was provided a recording of Trump's remarks by a person present for them, while The New York Times cited a person briefed on the remarks.

"I want to know who's the person, who's the person who gave the whistleblower the information? Because that’s close to a spy," Trump said, according to The Los Angeles Times. "You know what we used to do in the old days when we were smart? Right? The spies and treason, we used to handle it a little differently than we do now."

A U.S. official with knowledge of Trump’s remarks at the event told NBC News Trump also ripped the press as "scum."

Listen to the audio recording of Trump's remarks obtained by The Los Angeles Times.

Diplomats present for the remarks were taken aback to hear such explicitly political comments and attacks on the president's perceived enemies during an event for government workers, the official told NBC News.

In the complaint, which was made public with minimal redactions Thursday morning, the whistleblower makes it clear that a number of White House and administration officials provided information to him and that's largely what his claims are based on, in addition to information from previously published news stories.

From Trump Tower, where he was staying for the United Nations General Assembly, Trump sent out three dozen tweets and retweets in his defense over two hours on Thursday morning, continuing a week of persistent counterpunching at Democrats as they launched official impeachment proceedings against him.

Later Thursday, Trump again defended his call with the Ukrainian president, calling it "perfect" and accusing Democrats of blocking a domestic policy agenda that had little chance of getting anywhere even before the latest round of impeachment talks.

"What these guys are doing to this country is a disgrace, and it shouldn't be allowed. There should be a way of stopping it," Trump told reporters upon landing in Washington on his way back from New York.

As the acting director of national intelligence began to testify Thursday morning before Congress, Trump departed for a Manhattan fundraiser where he was to be surrounded by familiar faces from his former life as a New York businessman.

Raising money has been one bright spot for Trump. Adding to the $5 million haul the impeachment inquiry news brought in on Tuesday and Wednesday, the president raised $5 million at a fundraising dinner at a private home in Manhattan on Wednesday night, according to a Republican spokeswoman.

He was expected to bring in an additional $3 million at the breakfast Thursday morning, for a total of $13 million so far this week.

With his presidency facing what may be its biggest threat yet, Trump has cycled from offense to defense, reviving a strategy that he viewed as effective during Robert Mueller’s Russia investigation. He tried to downplay his request for the Ukrainian president to help investigate his political rivals, divert attention to actions by Democrats and presidential contender Joe Biden, and discredit the whistleblower as having partisan motives.

“Nothing has changed with the release of this complaint, which is nothing more than a collection of third-hand accounts of events and cobbled-together press clippings — all of which shows nothing improper,” said White House press secretary Stephanie Grisham in a statement Thursday morning. She added that “the White House will continue to push back on the hysteria and false narratives being peddled by Democrats and many in the mainstream media.”

But White House advisers privately have admitted they are now in uncharted waters.

Full coverage: Trump impeachment inquiry

The intelligence whistleblower, whose name has not been released, has said they lodged the formal complaint because they believed that Trump was "using the power of his office to solicit interference from a foreign country" in the 2020 election. In the call, Trump discussed having Ukrainian President Volodymyr Zelenskiy help investigate the Biden family’s business dealings.

"The interference includes, among other things, pressuring a foreign country to investigate one of the president's main domestic political rivals," the whistleblower continued. "The president's personal lawyer, Mr. Rudolph Giuliani, is a central figure in this effort. Attorney General Barr appears to be involved as well."

The complaint, which was released with minimal redactions, stresses that there are witnesses who can back up the account, and indicates concern over the handling of the White House record of the call.

The whistleblower says the record of the conversation on July 25 between Trump and Zelenskiy was treated in an unusual way, including part of it being over-classified, in the whistleblower's view.

Before the release of the whistleblower account there were already worries among Trump’s allies, particularly as it related to the involvement of Giuliani.

Two Trump allies, one of whom is a former senior White House official, described a level of concern inside the White House that is far greater than Trump and his supporters have publicly acknowledged. The former official added that Giuliani’s role is particularly problematic legally because he has purely political and personal ties to Trump and no official role with the U.S. government.

"It’s both better than I think many of us thought, given what some of the speculation was, and also worse than many of us thought given what some of the speculation was," the official said. "The way in which it’s worse than people thought basically has to do with Giuliani."