Ultimately, he will make a decision about what the administration will do if the program is challenged in court, he said in the Air Force One conversation that was allowed to be quoted on the record Thursday.
"It's a decision that I make and it's a decision that's very, very hard to make. I really understand the situation now," Trump said. "I understand the situation very well. What I'd like to do is a comprehensive immigration plan. But our country and political forces are not ready yet."
He added, "There are two sides of a story. It's always tough."
Earlier Wednesday, Trump's secretary of Homeland Security told lawmakers the DACA program could be in serious jeopardy.
Secretary John Kelly told Democrats of the Congressional Hispanic Caucus that while he personally supports the program, he could not commit to the Trump administration defending it, according to members in attendance and Kelly's spokesman, David Lapan.
Kelly said that legal experts he's talked to both inside and outside the administration have convinced him that it is unlikely the DACA program, the Obama administration's Deferred Action for Childhood Arrivals executive action, would sustain a court challenge.
Kelly said he has discussed DACA with Attorney General Jeff Sessions but wouldn't describe the contents of those conversations. Sessions is an immigration hard-liner who has been outspoken against the Obama administration policy.
"He did not indicate that they would (defend it). He didn't say that they wouldn't, but he didn't say that they would," said New Jersey Democratic Sen. Bob Menendez. "So between that and what he says is the legal analysis he's heard, it's not a pretty picture."
The issue may be forced later this year. There is a pending lawsuit on a related program, deferred action for parents of childhood arrivals, that will come up in September, and attorneys general from 10 states are threatening to add DACA to their complaints, which could force the administration to defend or abandon it.
Kelly suggested to lawmakers they work to pass immigration reform, but lawmakers expressed frustration that Kelly seemed to ignore the difficulty of passing legislation and the Republican opposition to extending DACA. They were also unhappy he seemed unaware there were any bills to make the program permanent, including the bipartisan BRIDGE Act and other proposals including from some Republicans -- "to which there was a combination of laughter and appalled shock in the room," said California Rep. Nanette Barragán.
The Democrats pressed Kelly to make his support for DACA more vigorous, suggesting he stand alongside them for a news conference as he did with Republican leadership when the House passed two bills cracking down on immigration enforcement. Kelly indicated he would consider doing so, but didn't commit.
"His urging is that Congress do something," Arizona Rep. Ruben Gallego said. "Our urging is: Don't be a fool. If you truly believe and Donald Trump believes that you should protect DACA, then the government should join and encourage the protection of DACA and fight against his attorney general."
"If you're going to count on Jeff Sessions to save DACA, then DACA is ended," Illinois Rep. Luis Gutiérrez said.
Trump himself pledged to "immediately" rescind DACA on the campaign trail, but after his election spoke about the difficulty of the issue for him as many of the recipients are honorable and contributing members of communities. The administration has continued issuing DACA permits under the program, angering many on the right who had hoped Trump would hold true to his pledge to end it.
This story has been updated with Trump's comments.