Jared Leto isn't a dad, as far as he knows.

"I may have some out there, you never know," he quipped with a smile when asked if he wanted kids one day, an irrepressibly coy answer from a star who famously plays his romantic cards close to the vest. 

But while he doesn't talk much about his personal life, Leto is open to baring his soul in song.

"This is a very intimate, very vulnerable, very revealing album," the Thirty Seconds to Mars frontman told E! News' Francesca Amiker in an exclusive interview ahead of the Sept. 15 release of the band's sixth studio album, It's the End of the World But It's a Beautiful Day.

Yet when asked specifically about tracks like "Get Up Kid," in which he sings, "Baby, it's bittersweet to love someone but to watch them leave / You took the wind out of me and knocked me off my feet," he took a turn for the cryptic.

"Love is war, some people would say," Leto said. "Love is complicated. Love is a delicate thing. But I did pour a lot of that" into these songs and "I talk about those things pretty openly on the album."

He also teased that the secret to his persistent My So-Called Life-era youthfulness at the age of 51 is also embedded in the release. But in the meantime, he cited his commitment to clean eating—"The diet is mostly made in the kitchen at this old ripe age," he noted—and active lifestyle for the reason he can still turn the world on with a shirtless snap. (Thought that isn't what their new single "World on Fire" is about.)

"You know I love to rock climb, I love the outdoors," Leto said, his predilection for scaling craggy peaks well-documented by now. "I'm on stage with Thirty Seconds to Mars playing shows, so I'm pretty active."

And just as his lifestyle brand Twentynine Palms bills itself as "sustenance for the body and psyche," so it goes that his band's first album in five years is intended as a balm for what's been existentially ailing you. 

While both sides of the coin are obviously represented in the title, It's the End of the World But a Beautiful Day, Leto said he remains "quite optimistic" about humanity's prospects despite all the global doom and gloom of the past several years. 

"Get Up Kid" is "a song to our younger selves," he explained. "It's a song to encourage us to continue to persevere, to put one foot in front of the other and keep marching on. And it's nice to have a song like that out in the world that could speak to people, maybe in some of their darker days, and remind us that, 'You know what, things are going to be ok.'"

Not that the Oscar winner, known for his dedication to his craft (whichever one he's focusing on at the time) as well as for his rock-hardened abs, doesn't have his struggles.

He definitely relates to what he sings about in "Avalanche" off the new album, "this Sisyphean thing, when you're pushing this boulder up the hill, only to find that when you get there it rolls back down again," he explained. But "that's kind of life, you know. If you want to do something special with your life—and it doesn't have to be some highfalutin or crazy thing, it can be a simple thing, to have a loving family, to raise your kids the best way you can. It could be to have a job that you're proud of and contribute to the world. Life has challenges and you've got to work hard, be determined." 

And quitting isn't an option for Leto, who'll be presenting a moon-person-shaped symbol of success to a winner at the 2023 MTV Video Music Awards on Sept. 12, so he tries not to get bogged down by the moments when life isn't firing on all cylinders.

"I don't often get to that place where I get that pessimistic," he shared. "I've certainly had that feeling for a moment, but I always continue to put one foot in front of the other. The thing that happens is, any of your favorite artists in the world are filled with fear and doubt and failure. But those things are all just a part of everyday life, and if you're reaching far, you're going to fail often. I wrote 200 songs just to get 11 that were good enough for the album."

Leto noted that he and bandmate/big brother Shannon Leto were first signed in 1998, and to still be releasing albums and touring the world after 25 years is "all icing on the cake." 

Describing the atmosphere at their recent Lollapalooza show as "absolutely insane," Leto emphasized how lucky they were to have "a really enthusiastic, very loud, very vocal audience."

That being said, while he's thrilled to be delivering new music to their devoted fans—some of whom Leto knows for a fact met their spouses at one of their concerts and went on to birth more fans— he had to overcome his usual angst about sending his musical baby off into the world.

"I'd like another month or two to prepare, to be honest," he cracked, "but they're going to rip it out of my cold, dead hands."

It's the End of the World But It's a Beautiful Day is out Sept. 15.