WASHINGTON – President Donald Trump threatened to file a "major" lawsuit against his opponents, repeatedly blasted the media as "corrupt" and reached for a barnyard epithet to describe the ongoing impeachment inquiry over his interactions with Ukraine.

He did all of it within a few dizzying hours at the White House.

After using Twitter to vent most of his fury at House Speaker Nancy Pelosi's decision to launch an impeachment inquiry, Trump burst into combat mode Wednesday – plucking from a chest of scandal-fighting tactics he has used since his early days as a Manhattan real estate developer.

"Just another day in paradise," Trump told reporters at one point. "Go write some phony stories."

Angry and defensive, Trump came out swinging at an East Room news conference with the president of Finland, telling a reporter who pressed him for an answer to stop being "rude," and airing a litany of grievances against Democrats, reporters and an unnamed whistleblower whose Aug. 12 complaint has left his White House reeling.

"I probably will be bringing a lot of litigation against a lot of people," Trump said, falling back on the legal threats he often used in business. "The whole thing is a scam."

Earlier, the president took to Twitter to describe Democrats as wasting their time on "bullshit." He said he didn't care about concerns, including from some GOP lawmakers, that his criticism of the whistleblower could intimidate others and make them more reluctant to come forward to report government abuse. He reiterated his contention that House Intelligence Committee Chairman Adam Schiff, D-Calif., was committing "treason."

As the term "TrumpMeltdown" trended on social media, photo agencies moved pictures of an angry-looking Trump with a reddened face.

Pelosi, Schiff and other Democrats said they are alarmed at the whistleblower’s report and a summary of a July 25 phone call between Trump and Ukrainian President Volodymyr Zelensky that has been made public. On the call, Trump repeatedly pressed Zelensky to investigate Biden, the 2020 Democratic presidential frontrunner, and his son, Hunter, who once had business interests in Ukraine.

During the time of the conversation, the White House was holding up a military aid package Congress had approved for Ukraine.

The whistleblower has accused Trump of abusing the power of his office to try to discredit a political rival. Trump and Zelensky have said there was nothing improper about the call and the president insisted he did not use the money as leverage to pressure the Ukrainians to dig up dirt on Biden.

Trump lashed out at Schiff during an Oval Office meeting with Finland's president, Sauli Niinisto, who was visiting Washington. Trump told reporters that the Democrat and key figure in the inquiry couldn't carry Secretary of State Mike Pompeo's "blank strap," an apparent reference to a "jockstrap." Earlier, Trump blasted Pelosi's stated desire to work on trade and drug prices, saying Democrats were obsessed with impeachment.

Left unsaid in Trump's responses was just how much cooperation Congress can expect from the White House. Trump declined to answer a specific question about whether he will honor subpoenas over the Ukraine call that Democrats promised by week's end. He also did not answer a question about what he wanted Zelensky to do about Biden.

Docs:Democrats threaten to subpoena White House for documents

"Did you hear me? Did you hear me? Ask him a question. I've given you a long answer. Ask this gentleman a question. Don't be rude," Trump said to a reporter during his press conference, indicating that he should ask the Finnish president a question instead.

"No, sir, I don't want to be rude. I just wanted you to have a chance to answer the question that I asked you," the reporter said.

"I have answered everything," Trump fired back. "It's a whole hoax. And you know who's playing into the hoax? People like you and the fake news media that we have in this country."

Trump's longtime critics saw a president in crisis.

"This is not a well man," said Rick Wilson, an anti-Trump Republican strategist.

Though he remained active on Twitter, Trump mostly avoided questions in the days after the impeachment inquiry was announced. He took four questions at a press conference at the end of his trip to the United Nations last week, far fewer than usual, and spoke in a hushed, almost monotone voice. His public schedule in recent days – either by design or coincidence – has put him in front of reporters less frequently than usual.

But he returned Wednesday to the pugnacious style that has fired up his supporters for years.

With the focus on the impeachment inquiry, far less attention was paid to some of the subtler tensions that appeared to develop between Niinisto and Trump. The Finnish president offered his extended thoughts about climate change, an issue rarely discussed publicly at such meetings. He also seemed to criticize Trump's posture toward Europe.

"We all know Europe needs (the) USA, but I say that (the) USA needs also Europe," Niinisto said as he stood alongside Trump in the East Room of the White House. "The stronger Europe we have, the stronger partner you have."

At the start of the news conference, Trump joked to his Finnish counterpart: "Look at all of the press that you attract. Do you believe this? That's very impressive."

Without missing a beat, Niinisto shot back: "I guess they are not after me."

Contributing: Courtney Subramanian