The actor took to his Instagram Story on Monday to post a photo of Noah's oil painting of a mountain landscape. Alongside the pic, Green, 48, shared that Noah, 8, is in the "same art class" as North, 8.
As fans can recall, earlier this year, Kim posted a shot of a painting of a mountain landscape, like Noah's art, claiming North was the artist. However, many social media users weren't convinced the 8-year-old created the painting, prompting Kim to hit back at the critics.
In his post on Monday, Green praised North's artistic talent, adding that although it may be hard to believe, his son and North actually painted the stunning landscapes.
"Someone just told me that Kim K was given a hard time for posting a pic of a painting North had done. Noah is now working on the same thing in the same art class," wrote Green, who shares son Noah, as well as sons Bodhi, 7, and Journey, 5, with ex Megan Fox.
"It's unbelievable but true," the "Beverly Hills, 90210" star added. "The kids are painting these and Norths is beautiful."
Taking to her Instagram Story back in February, Kim, 41, shared a photo of an oil painting that featured beautiful, snow-capped mountains, a river and a green valley covered in flowers. The "Keeping Up with the Kardashians" star said the Bob Ross-style painting was created by North West. "My little artist North," she wrote alongside the photo.
Waiting for your permission to load the Instagram Media.
Despite Kim saying the painting was a North West original, many people voiced their doubts on social media. In response, Kim slammed critics in a lengthy statement shared to her Instagram Story.
"DON'T PLAY WITH ME WHEN IT COMES TO MY CHILDREN!!!" she wrote at the time, per TMZ. "My daughter and her best friend have been taking a serious oil painting class where their talents and creativity are being encouraged and nurtured."
"North worked incredibly hard on her painting with took several weeks to complete," she added. "As a proud mom, I wanted to share her work with everyone."
Kim continued to blast the social media users who questioned whether North was in fact the artist.
"I'm seeing op-ed pieces in the media and social media from grown adults breaking down whether or not my child actually painted this," she wrote. "How dare you see children doing awesome things and then try to accuse them of NOT being awesome? Please stop embarrassing yourselves with the negativity and allow every child to be GREAT!"
"NORTH WEST PAINTED THAT PERDIOTDDDDDABCDEFGZFDT!!!!!!!!!!!!!!!!!" she concluded.
The reality star also posted a snap of a similar-looking painting North's friend, Ryan Romulus, created. "Ryan's amazing painting!!!" she wrote. "Two beautiful artists."
Meanwhile, Ryan's mom, Tracy, also took to social media, pointing out that North and Ryan are "learning oil painting techniques from an instructor."
"They spend weeks at a time on a single painting and are incredibly proud of themselves once they complete a project," she wrote on her Instagram Story at the time, according to PEOPLE. "They are following a curriculum but the works are original, starting from a blank canvas and each child's interpretation."