And he staunchly defended his relationship with President Donald Trump, who encouraged him to speak with reporters about his role in the Epstein matter amid calls for his resignation. Afterward, officials said Trump remained supportive of his labor secretary.
"Facts are important and facts are being overlooked," Acosta told reporters at the Labor Department in Washington, insisting that his office had secured a reasonable sentence facing an uncertain trial with reluctant witnesses. "These cases are complex, especially when they involve children."
In the afternoon news conference, Acosta cast his decision to negotiate a non-prosecution deal with the multimillionaire Epstein as a catch-22: while the terms were softer than he'd have preferred, it provided a more certain outcome than going to trial, which he said amounted to a "roll the dice" proposition.
Acosta claimed his office intervened when state prosecutors were planning to go after Epstein on lesser charges. He said his priority was ensuring that Epstein went to prison, paid restitution to his victims and registered as a sex offender.
Epstein was ultimately sentenced to time behind bars -- but served only 13 months and was allowed to leave for long stretches to work from his office. He avoided a federal trial, but did have to register as a sex offender.
Acosta framed the terms of the agreement as the product of career prosecutors, not his own. And he suggested that shifts in the way society views victims of sexual crimes meant his actions were being viewed different now than they were a decade ago.
"I know in 2019, looking back at 2008, things look different," Acosta said, alleging that "today's world treats victims very, very differently."
He wouldn't say whether he would make the same decision now.
"No regrets is very hard question," Acosta said, adding later: "You always go back and say 'what if?' What I can say is at the time ... this was the view of the office."
Asked what he would say to Epstein's victims -- many of whom have expressed outrage at the plea agreement's terms -- Acosta did not apologize.
"The message to victims is come forward," he said.
Acosta was blasted by former Palm Beach State Attorney Barry Krischer after the news conference for his remarks.
"As the State Attorney for Palm Beach County for 16 years (1993-2009), which included the entire period of the Epstein investigation, I can emphatically state that Mr. Acosta's recollection of this matter is completely wrong," Krischer wrote in a statement obtained by CNN.
"Mr. Acosta brokered a secret plea deal that resulted in a Non-Prosecution Agreement in violation of the Crime Victim's Rights Act. Mr. Acosta should not be allowed to rewrite history."
A number of Democrats, including many contending for the 2020 presidential nomination, have called on Acosta to resign.
During a phone call Tuesday afternoon, Trump instructed his labor secretary to hold the press availability, two people familiar tell CNN. The appearance was viewed widely as a performance for the President as he weighs his support for the embattled cabinet member.
Two White House officials said afterward that Acosta handled himself well at the news conference and retained Trump's support. One said Acosta likely gave his defenders more information to counter accusations that he was too lenient in the Epstein case.
The President has made clear to his aides that he wants Acosta to keep his job and that he continues to have an affinity for him, another official said.
Trump said on Tuesday he would look into Acosta's role in the Epstein matter. He has privately said he has confidence in Acosta, according to people familiar with his remarks.
Trump said Tuesday that "a lot" of people were involved in the 2008 case in addition to Acosta.
"I can only say this from what I know and what I do know is that he's been a great, really great secretary of labor," Trump said. "The rest, we'll have to look at it, we'll have to look at it very carefully. But you're talking about a long time ago and again it was a decision made, I think, not by him but by a lot of people. So we're going to look at it very carefully."
However, Trump's associates believe that confidence could disappear quickly. The President's longtime friend Chris Ruddy told CNN's Don Lemon on Tuesday that he believes Acosta will be out in a matter of weeks, though he said he has not spoken to Trump about the matter.
Acosta's future in the Trump administration is likely to depend on news coverage of his role in Epstein's plea agreement and how loud the calls for his resignation become, according to people close to Trump.
Acosta does not have a wealth of support in the West Wing and has taken on a low profile, according to officials, so it could be more difficult for him to hang on. But Trump has previously been wary of firing Cabinet officials because it fuels the sense his administration is in chaos.
Acosta insisted Wednesday he enjoys an "outstanding" relationship with Trump and his staff.
"He has publicly made clear that I've got his support," Acosta told reporters, adding he'd received a call earlier Wednesday from acting White House chief of staff Mick Mulvaney meant to dispel reports the two men were in a dispute.
"Our relationship is excellent," Acosta said Mulvaney told him. "Articles to the contrary are BS."
CNN's Jim Acosta, Pamela Brown, Betsy Klein and Curt Devine contributed to this report.