By Arlette Saenz, CNN

(CNN) -- Former Vice President Joe Biden reflected Sunday on how he wants to spend the rest of his life, saying he wishes to remain "engaged in all the issues that have animated my life" and "spend as much time" as he can with his family.

At a book tour event in Burlington, Vermont, on Sunday afternoon moderated by author Jodi Picoult, Biden was asked how he wants to spend the rest of his life. Some in the audience yelled "run, Joe, run!" and "2020," prompting cheers and applause, but Biden didn't bite. The former vice president is considering whether to launch a run for the White House in 2020 and has said he'll make a decision within the next two months.

"I want to be able to, when my life is finished, be able to say to myself that I kept my commitment to Beau, that I didn't walk away, that I stayed engaged in all the issues that have animated my life my whole life," Biden said Sunday. "I want to spend as much time as I can with my family. I have five grandchildren who adore me."

"I literally text or speak to every one of my grandchildren every single solitary day," Biden added. "Beginning, middle and end is family."

That commitment the former vice president made to his late son Beau Biden is at the center of his memoir, "Promise Me, Dad." Biden was promoting the paperback version of the book at the event.

Biden also discussed his decision not to run for president in 2016 in the months after Beau's death from brain cancer at the age of 46, noting that his son Hunter and daughter Ashley thought a campaign could be beneficial to their grieving family.

Biden said he "went out in the Rose Garden with the President, my wife and announced I wasn't going to seek the nomination -- even though my son and daughter thought that we should because they thought that the pressure would bring us all together, keep us tight. My son says we do best under pressure, and we all had one purpose to focus on the entire family, but I just didn't have the courage to do it."

The former vice president was also asked to weigh in on whether he thinks changes the Trump administration has made can be reversed down the road. He expressed optimism on the domestic front "assuming something changes in two years," but expressed concern about the administration's impact on foreign policy.

"I think on the domestic policy front we can change it back," Biden said. "On foreign policy, I'm more worried. I'm more worried because I think if we have ... six more years of the last two years, I think you'll see the end of NATO. I think you'll see the end of our alliance."

Biden's event took him to the home state of a potential future opponent -- Bernie Sanders, the independent Vermont senator who ran for president in 2016. The sold-out event was held at the Flynn Center for Performing Arts, which holds about 1,400 people and was the site of a January 2016 rally from then-candidate Trump.