On videos circulating on social media, the two rappers got into an altercation at the Harper's Bazaar party in NY on Friday night.
But sources close to Cardi B told the website the artist was not looking for a fight and that she only wanted to address "lies" that were allegedly being spread.
Security immediately stepped in to calm the situation.
The rapper, who has achieved huge success over the previous year with hits such as Bodak Yellow and I Like It, said she had let a lot of things slide.
Cardi was referring to Kulture - her daughter with fellow rapper Offset - who was born in July.
Cardi then accused Nicki of questioning her abilities as a parent.
I googled this rah Ali woman.
According to the outlet's eyewitnesses, Cardi "aggressively approached the table" and then said to Nicki, 'Let me tell you something'. Cardi was seen leaving the party with no shoes.
"I've let a lot of s**t slide! I let you talk big s**t about me!"
"I addressed you once in person, I addressed you a second time in person, and every time you copped a plea!" "No, b***h. I still don't like you b***h". I've worked too hard and come too far to let anybody fuck with my success!
Nicki Minaj was criticized after she compared herself to Harriet Tubman ahead of her appearance at the 2018 MTV Video Music Awards.
"Fans and people, they really want to see that happen because it's really entertaining", she said in an interview on Beats 1 Radio.