WASHINGTON — (CNN) Donald Trump indicated to Mike Pence late Wednesday night on the phone that he is moving toward choosing the Indiana governor as his vice presidential nominee, a source familiar with the process tells CNN.

Pence’s team has gotten word to start preparing to get the official nod Thursday, and the Trump campaign is currently planning for a scenario with Pence as the running mate, according to two sources familiar with the process.

The Pence campaign has all the paperwork prepared and ready to file to take him off the ballot to run for reelection as governor and meet the Friday deadline.

But until an offer is made and accepted, nothing is for certain in this very fluid situation. Earlier on Thursday, a Trump adviser cautioned Trump’s leaning could change.

Former House Speaker Newt Gingrich, also under consideration, had no comment when asked about the latest developments.

He told CNN earlier Thursday that he expects to be informed of the decision around 1-2 p.m, and tweeted that he will do a Facebook live to discuss the matter at 2 p.m.

The real estate mogul is slated to announce his decision Friday at 11 a.m. in New York, and multiple sources have said Trump’s shortlist is down to Pence, New Jersey Gov. Chris Christie and Gingrich.

Top Trump officials urged caution as the process played out.

Trump campaign chairman Paul Manafort tweeted: “Re: @realDonaldTrump VP selection, a decision will be made in the near future and the announcement will be tomorrow at 11am in New York.”

Jason Miller, Trump’s senior communications adviser, added: “A decision has not been made by Mr. Trump. He will be making a decision in the future … and will be announcing his Vice Presidential pick tomorrow at 11am as planned.”

Adding intrigue to the day, Pence’s deputy campaign manager, Marc Lotter, was spotted at Indianapolis airport Thursday waiting to board a flight to New York City.

He told CNN that he had meetings in the city for the campaign — before specifying that it was for the Pence campaign, not Trump’s.

“I have no information that I can confirm or deny,” he told reporters on the plane.

Asked what his gut feeling was, Gingrich told CNN that he “would not be at all surprised if it was Pence.”

“Mike’s got a lot of strengths and he’s substantially younger. I’m two years older than Trump and Pence is 20 years younger than me. I think having somebody who represents a somewhat younger voice would have some advantages,” he said.

Trump is spending the day in California, attending fundraisers in the Los Angeles area while his potential running mates awaited word on the other coast.

Pence is in Indiana, where he was spotted going for a bike ride with his wife in the morning.

Gingrich was also home in McLean, Virginia, and was seen taking out the trash in the morning before driving to his office in Arlington, Virginia. Christie is in New Jersey while Sessions is back in Washington after his trip to Indiana on Wednesday.

Trump’s latest leaning comes after the billionaire spent 24 hours in Indiana where he spent much of his time with the conservative Indiana governor, who Tuesday evening joined Trump at a fundraiser, a rally and later dined with him.

The two men also shared breakfast Wednesday morning at the governor’s residence, where they were joined by Trump’s adult children, who are all influential in Trump’s decision-making process.

A separate Trump adviser told CNN on Wednesday that Trump’s “gut” was pushing him to pick Christie, the outspoken New Jersey governor.

Pence’s selection would give Trump a running mate with strong ties to the Republican base — particularly social conservatives.

As governor, he faced major political backlash over his decision to sign into law a “religious freedom” measure that infuriated major businesses that saw it as anti-LGBT.

He also signed a restrictive anti-abortion measure into law.

He was among the first Republicans to embrace the tea party on Capitol Hill.

Pence, as a former congressional leader, also has ties to the Koch brothers and other influential donors who have so far stayed away from Trump.

A Pence campaign official told CNN Wednesday night that it is still moving forward with cutting gubernatorial re-election ads, knocking on doors and other campaign activities until getting the final word from the governor.

This official added that Pence has until noon on Friday to decide whether or not to pull his name off the ballot as governor — something he’d have to do in order to run as Trump VP, because of Indiana law.

Of course, gubernatorial campaign ads can be ordered and then shelved, this official noted.

Harry Reid, the top Senate Democrat, had sharp words for Trump, regardless of who he selects.

“It’s not going to help him no matter who it is,” the Nevada Democrat told CNN’s Manu Raju on Thursday.