Steven Tyler thinks Nicki Minaj and Mariah Carey need to work on their friendship.

The Aerosmith frontman - who was a judge on 'American Idol' for two seasons - thinks the 'Moment For Life' rapper and the 42-year-old singer should be professional judges on the upcoming series of the talent show and focus on the contestants.

The 64-year-old 'Out Go The Lights' singer told MTV News: ''You just have to give your opinion. It wasn't hard for me, but I would imagine it's hard for some people, and they need a manager to say 'Shut the f**k up, and just give them your opinion'.

''I know that they've got something going on on the judges' panel, [and] it shouldn't be that, it should be just the opposite: They should have something going on, which is called 'camaraderie'.''

Steven believes it is essential for the female judges to put aside their differences if they are to nurture new talent like last year's winner Phillip Phillips.

''They should have something going on so thick and beautiful that they can lay it over the new talent that's trying to birth itself. It needs to be birthed, not judged by 'entertainment' factors, it needs to be judged by people that [are] honest, true, that have the 'it' factor. Not the 'it' factor because they can fight. The f**k is that all about?''

Nicki, 29, recently opened up about how her feud with Mariah and said despite not getting along well they had great chemistry.

She said: ''The chemistry of the judges, I feel it while I'm there. I think it's really different from anything we've seen before on Idol and people are going to like it.''

She also hinted the rivals might be on friendlier terms now and could even perform on the show together.

She said: ''If she'll have me, I'll be there waiting.''