Mr Charles, who has more than 25 million subscribers on YouTube, shared a statement in February saying he believed a boy he had been messaging on Snapchat was 18.
In Thursday’s video, he said: “I f****d up. These conversations should’ve never happened, point-blank, period. There is no excuse for it, there is no ifs, ands or buts and I take full responsibility for that.”
YouTuber James Charles has admitted sending “flirty” messages to underage boys.
The 21-year-old beauty influencer shared a 14-minute video titled “holding myself accountable” and apologised for engaging in conversations with two 16-year-olds on Thursday.
Allegations that Mr Charles had groomed a minor emerged on social media earlier this year.
Mr Charles said he should have taken a closer look at the boys’ social media profiles and realised their true ages.
He added: “As an adult, it is my job and my responsibility to verify who I’m talking to, and therefore there is no one else to blame for this but myself.”
Mr Charles also used the video to apologise publicly to the boys, saying: “To the guys involved in the situation, I want to say I’m sorry.
“I’m sorry that I flirted with you and I’m really sorry if I ever made you uncomfortable. It is completely unacceptable.”
Mr Charles said his behaviour was “reckless” and stemmed from the fact he was “desperate” for a relationship. He said he was “absolutely” not looking for a younger boyfriend.
“I promise something like this will never ever happen again … I hope to never disappoint you again,” the American influencer said.
The recent allegations are not the first time Mr Charles has faced controversy.
He was previously accused of inappropriate behaviour and of trying to “manipulate” people’s sexuality in 2019 when fellow YouTuber Tati Westbrook said Mr Charles had tried to “trick a straight man into thinking he’s gay”.
Following those allegations, Mr Charles shared a video, saying: “I’m sorry for everything that I put you through.”