The Justice League star, 43, asked fans to send "all the mana, all the aloha, all the love" after he visited Snyder, 44, on Friday night in his Los Angeles hospital room, where the Color Run founder is currently sick with RSV pneumonia and "no immune system" after beating COVID.
As he exited the hospital after removing his PPE gown and mask, Momoa explained that Snyder is suffering from RSV and pneumonia after recovering from COVID, which had him in the ICU for 72 hours. "There's my buddy up there," Momoa prefaced the clip from the parking lot.
He continued: "The guy's had leukemia four f—ing times. He beat it. And he just got COVID for the first time, and he beat it. And now he's got RSV and pneumonia, and he needs all the love and all the support he can get."
"So, if you can, it would be amazing, and it would be a big honor and favor to me if you could just pump him up," said Momoa. "He's doing really well. He's beating the cancer, but these fucking other things are just getting his ass. It's hard for him to breathe."
Respiratory syncytial virus (RSV), which often causes mild, cold-like symptoms, can also cause a lung infection or pneumonia in adults with chronic medical conditions and weakened immune systems, according to the Centers for Disease Control and Prevention. RSV can also cause asthma, COPD and congestive heart failure.
Momoa and Snyder previously spoke to PEOPLE last May about their friendship as they attempted to get more potential donors for the national Be the Match Registry when he was in need of a blood stem cell transplant.
"We met through happenstance and mutual friends after my first cancer battle [with acute myeloid leukemia] in 2015," Snyder said. "I think in the aftermath of treatment, I was very focused on living every day with purpose and my heart was open. And Jason wasn't quite as busy then, and he lives with such a big giving heart and Aloha, we just connected instantly."
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He added: "Some of my friends kind of shrink when you're in trouble, or it becomes kind of surface-y. And Jay was just right there again."
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Momoa said that Snyder's sickness is "really my first experience" with cancer, explaining: "And something like this, absolutely, I can donate my time and platform. I just want to be able to help… It's just tearing me up that I can't save my buddy."