Rapper J Cole says he feels "terrible" after releasing a diss track aimed at Kendrick Lamar and has vowed to delete it.

The American musician released the song titled 7 Minute Drill on Friday, in which he branded fellow US rapper Lamar's latest album "tragic".

The row began last year after Cole suggested he, Lamar and Drake were the "big three" of the modern rap scene in the song First Person Shooter.

The trio have dominated the genre since the 2010s, with Lamar winning 17 Grammys, Drake five and Cole two.

But Lamar rejected Cole's suggestion they were equals when he featured on a track called Like That by rapper Future and producer Metro Boomin.

In one verse, Lamar said there was no "big three," adding: "It's just me." He also criticised some of Drake and Cole's work.

| Drake hasn't directly responded to Lamar's criticism. Pic: AP

In response, Cole included 7 Minute Drill on his new mix tape Might Delete Later, in which he said Lamar "fell off like The Simpsons", alongside other insults about his career declining.

But Cole has already promised to delete the track from streaming platforms, telling the crowd at a festival he headlined on Sunday it was "the lamest, goofiest sh*t" he had ever done.

Speaking at Dreamville Festival, he said he felt pressure to respond after Lamar's "bazooka" of a verse, but he was "conflicted" because he was "blessed to stand beside" him and Drake.

In a three-minute rant, he said he felt bad about his track's contents and it "don't sit right with me", adding: "The past two days felt terrible".

He asked the crowd: "Y'all love Kendrick Lamar, correct? As do I."

Cole said he was praying Lamar had not taken offence, adding that if he had, he would take criticism from him "on the chin" before asking for forgiveness from his fans "for the misstep".

Drake hasn't responded to Lamar's insults directly, though he appeared to reference it during a concert shortly after Like That was released.

"I got my head up high, my back straight, I'm feeling 10ft f***ing high," he told a crowd while on stage.