(CNN) Former US attorney Preet Bharara on Sunday talked about the three times Donald Trump called him, and the one time he didn't answer.
Bharara was a US attorney until March, when the President fired him after Bharara refused to resign along with a raft of other Obama-era Justice Department attorneys. The sudden showdown came after several interactions with Trump during his transition to the presidency, when Bharara said he had two "unusual phone calls" with him.
"When I've been reading the stories of how the President has been contacting (former FBI Director) Jim Comey over time, felt a little bit like deja vu," Bharara said on ABC's "This Week."
Trump invited Bharara to Trump Tower in New York a few weeks after the election, and Bharara said Trump asked him to stay on at the time.
Bharara said Trump called him twice during the transition "ostensibly just to shoot the breeze."
"It was a little bit uncomfortable," Bharara said. "But he was not the President. He was only the President-elect."
The former US attorney said Trump called him one more time -- in March, after Trump had taken office.
"I refused to return the call," Bharara said.
He said he talked to his team and reported the phone call to Attorney General Jeff Sessions' chief of staff, saying it appeared Trump "was trying to cultivate some kind of relationship."
Bharara explained it was important for him to stay at "arm's length" from the President given the then-US attorney's jurisdiction over business interests, including the Trump Organization's, in New York.
He also argued that Trump knew such outreach was problematic.
Bharara said 22 hours after he declined to return the call, he was asked to resign along with the other US attorneys.
In the interview Sunday, Bharara said he thought there is enough evidence to open an investigation against Trump for obstruction of justice, but he warned people from jumping to a conclusion either way.
"No one knows right now whether there is a provable case of obstruction," Bharara said.
He said he suspected Department of Justice special counsel Robert Mueller would look at obstruction of justice as part of the executive branch's investigation, saying it would be a reasonable assumption "if Bob Mueller is looking at everything that you would expect him to look at. Good prosecutors look at everything. And this would seem to be one of those things that he was looking at."
Bharara attended the Senate intelligence committee hearing featuring testimony from Comey on Thursday. Comey told the committee that Trump asked him to drop an investigation into former national security adviser Michael Flynn during a private Oval Office meeting in February.
In a press conference Friday, Trump denied doing that, but also said "there would be nothing wrong" if he had.
Flynn resigned in February after it emerged that he had misled Vice President Mike Pence about phone calls he had with Russian Ambassador Sergey Kislyak.