President Trump is preparing to push out a national security official who testified against him during the impeachment inquiry after he expressed deep anger on Thursday over the attempt to remove him from office because of his actions toward Ukraine.

Lt. Col. Alexander Vindman — a National Security Council aide who testified during House Democrats’ impeachment hearings — will be informed in the coming days, likely on Friday, by administration officials that he is being reassigned to a position at the Defense Department, taking a key figure from the investigation out of the White House, according to two people familiar with the move who spoke on the condition of anonymity because they were not authorized to discuss personnel decisions.

Vindman had already informed senior officials at the NSC that he intended to take an early exit from his assignment and leave his post by the end of the month, according to people familiar with his decision, but Trump is eager to make a symbol of the Army officer soon after the Senate acquitted him of the impeachment charges approved by House Democrats.

Trump made clear on Thursday that he is ready to make his impeachment a key part of his reelection strategy and highlight his anger at Democratic leaders who led the charge to remove him from office, as well as Republicans who did not embrace the defense of his actions even though he was acquitted by the Senate on Wednesday.

At an event in the East Room of the White House, he called Speaker Nancy Pelosi (D-Calif.) a “horrible person” and derided Sen. Mitt Romney (R-Utah) as a flip-flopping Republican with “no sign of principles” whose vote to convict Trump on abuse of power charges was born not out of principle but bitterness over his failed 2012 presidential bid.

And he kicked off the day at the National Prayer Breakfast by questioning the two lawmakers’ claims about the role religion plays in their public lives.

“I don’t like people who use their faith as justification for doing what they know is wrong. Nor do I like people who say, ‘I pray for you,’ when they know that that’s not so,” he told a room full of religious leaders.

Trump and his allies are considering doing more than just launching verbal fusillades at his perceived enemies over impeachment as the decision regarding Vindman shows. Some of the president’s aides are discussing whether to remove or reassign several administration officials who testified during the impeachment inquiry, according to aides and advisers who like others spoke on the condition of anonymity to discuss the plans. Meanwhile, Senate committee chairmen are ramping up their investigation into Hunter Biden’s work in Ukraine while his father, Joe, was vice president.

“Lieutenant Colonel Col. Vindman and his twin brother — right? — we had some people that — really amazing,” Trump said during an event at the White House, mocking the national security counsel aide who testified during hearings investigating the White House’s actions toward Ukraine.

Trump has complained about Vindman in private, mocking the way he spoke, wore his uniform and conducted himself during the impeachment inquiry, according to people familiar with his remarks. He has discussed with aides removing other national security officials who testified or cooperated with House Democrats, with Trump calling them disloyal and asking whether he should further cull his national security staff after impeachment. He remains incensed that so many people in his administration testified last year, according to allies of the president. No final decisions have been made on what to do with the officials, these people said.

But the White House is not hiding from the fact it would like to see Democrats and Romney feel some pain for their role in his impeachment.

Stephanie Grisham, the president’s press secretary, said making people pay for their conduct was a reason Trump held an event Thursday in the East Room of the White House, which Trump later said was not a speech but a “celebration” of his acquittal by the Senate a day earlier.

Advisers to the president said Trump is already thinking about a scorched-earth nine-month campaign and how Democrats might attack him next — and how he can land punches of his own.

“He’s keenly aware of the fact that the Democrats only have one play: to destroy him personally every single day … until November,” said Jason Miller, an informal adviser and former campaign aide.

Additionally, Trump sees it as valuable to frame previous investigations as witch hunts because he expects more probes, Miller and other Trump allies said, and the president has told his aides that Democrats will continue to investigate his finances, his Cabinet officials and his interactions with foreign leaders.

Trump was not in a reflective mood about his conduct on Thursday.

He was impeached by the House on charges that he abused his office and obstructed Congress. The crux of the case against him is the allegation that he withheld military aid and a White House meeting to pressure Ukraine to investigate Joe and Hunter Biden — who served on the board of Burisma, a Ukrainian energy company, while his father was vice president — as well as a widely discredited theory that Ukrainians interfered in the 2016 U.S. presidential election.

Trump has denied any wrongdoing and — despite some Republican senators calling his action wrong even if not impeachable — he has shown no remorse.

That was evident from the time he left the White House on Thursday morning on his way to the prayer breakfast being held at a nearby hotel.

He rewrote parts of his speech for the event, scribbling en route, to highlight his impeachment and attack his foes at a traditionally staid, nonpartisan affair, according to officials. When Arthur Brooks, a conservative columnist, encouraged guests at the breakfast to “love your enemies” and set aside contempt, Trump pointedly said that he did not concur.

“I don’t know if I agree with you. I don’t know if Arthur is going to like what I’m going to say,” he said, before attacking both Pelosi and Romney from the dais at the Washington Hilton.

His event in the East Room later in the day was part celebration, part tirade as he thanked his supporters and laid into his critics.

“They are vicious and mean, vicious. These people are vicious,” he said of Democrats before focusing specifically on Pelosi and House Intelligence Committee Chairman Adam B. Schiff (D-Calif.), who led the impeachment inquiry.

He brought up Hunter Biden, criticizing his role in Ukraine and mocking him for being discharged from the Navy Reserve after allegedly testing positive for cocaine.

Trump plans to repeatedly bring up the younger Biden on the campaign trail, according to White House officials, hoping to use it against Joe Biden, a 2020 Democratic presidential candidate, and to argue that Democrats are corrupt. Neither Biden has been charged with any wrongdoing by Ukrainian officials.

Trump has continued to suggest to aides that his personal lawyer, Rudolph W. Giuliani, could have valuable information and that Hunter Biden resonates with the general public.

He may get help on this topic from Senate Republicans.

In a letter sent Wednesday to the head of the Secret Service, two Senate committee chairmen wrote that they are “reviewing potential conflicts of interest posed by the business activities of Hunter Biden and his associates during the Obama administration, particularly with respect to his business activities in Ukraine and China.”

Sens. Charles E. Grassley (Iowa) and Ron Johnson (Wis.) said they are seeking information on any instances when Hunter Biden traveled with a protective security detail during the time his father was vice president, as well as when he flew on government planes.

Trump has been convinced by polling and rallies in recent months that relentlessly attacking Pelosi is key to his reelection success, and he has shown flashes of anger when discussing her, according to aides.

Republican lawmakers and Trump have also discussed ways to exact revenge on Schiff for his leading role in the president’s impeachment, according to people familiar with the conversations.

Some White House, campaign and congressional officials are pushing Trump to move on from talking about impeachment or attacking Romney, the lone Republican to vote for his conviction. RNC and campaign officials said they were happy Thursday that Trump did not seem to have a specific plan to take on Romney, even as the White House lashed into him in a long page of talking points.

“There’s a lot of anger there. But I think this, too, shall pass,” said Rep. Chris Stewart (R-Utah), a Trump ally.

One top ally suggested the president should go to Florida, golf for a few days and bask in the sun with his friends — or turn his focus to attacking Sen. Bernie Sanders (I-Vt.) or attempting to sow division among the Democratic 2020 nominees.

Trump’s allies said he is in his strongest political position in years. His poll numbers rose during impeachment, with Gallup showing him at 49 percent approval, and the economy is performing well overall. Voters have not yet coalesced around a candidate in the splintered Democratic presidential field. And with the impeachment probe and the Russia investigation over, no investigative threat currently appears to loom over the president.

Aides said the mood in the West Wing is brighter than it has been in many months.

“Look at the successes we’ve had. Contrast that to the Democrats,” House Minority Leader Kevin McCarthy (R-Calif.) said.

But Trump was unable to hide his anger in public on Thursday and it’s unclear when or if he will stop focusing on his impeachment and investigations into his administration.

“We’ve been going through this now for over three years. It was evil. It was corrupt. It was dirty cops. It was leakers and liars,” he said in the East Room. “And this should never, ever happen to another president, ever.”

Mike DeBonis and Colby Itkowitz contributed to this report.