The commutation was announced Tuesday, prompting questions about what will happen to other people who leak government information.
"Chelsea Manning has served a tough prison sentence," Obama said. "So the notion that the average person who was thinking about disclosing vital classified information would think that it goes unpunished — I don't think would get that impression from the sentence that Chelsea Manning has served."
Manning was sentenced to 35 years in prison in 2013, and she will now be released on May 17. Her lawyer released a statement after the announcement that her sentence was commuted saying that her time in prison included "long stretches of solitary confinement — including for attempting suicide."
In the wide-ranging press conference, Obama touched on a number of topics, starting with the importance of a free press, then fielding questions about immigration policy, voting rights and his plans for post-presidential life, among others.
"I want do some writing. I want to be quiet a little bit and not hear myself talk so darn much. I want to spend precious time with my girls. So those are my priorities this year," he said.
He also spoke about possible political changes during the Trump administration or news that could prompt him to speak out about proposals after he leaves office.
Those situations, Obama said, would be only in "certain moments where I think our core values may be at stake."
He said some of his concerns could include "efforts to round up kids who have grown up here and for all practical purposes are American kids and send them someplace else when they love this country" and "institutional efforts to silence dissent for the press."
Obama also said at the start of his remarks that he had been in touch with the Bush family about former President George H.W. Bush and former first lady Barbara Bush, who are both hospitalized.
"They have not only dedicated their lives to this country — they have been a constant source of friendship and support and good counsel for Michelle and me over the years," Obama said. "They are as fine a couple as we know, and so we want to send our prayers and our love to them. Really good people."
The final question was a personal one, with Obama weighing in on how his daughters reacted to the presidential election, starting with some admitted bragging.
"Man, my daughters are something," Obama said. "And they just surprise and enchant and impress me more and more every single day as they grow up."
"It was really interesting to see how Malia and Sasha reacted. They were disappointed. They paid attention to what their mom said during the campaign and believed it because it's consistent with what we have tried to teach them in our household and what I've tried to model as a father with their mom and what we've asked them to expect from future boyfriends or spouses. But what we've also tried to teach them is resilience and tried to teach them hope and that the only thing that is the end of the world is the end of the world," he said.