Absolutely, it is not necessary.

good question

Some journals ask for that as a condition to accept the paper

I think, the citation is good and necessary, it means that the authors respect the journal, as a result, the journal will consider the paper for review process.

Best Regards

Absolutely, it is not necessary.

It's not necessary

It is not necessary if there is not papers from your filed of interest, but some Editors ask you to put 2-3 references from their Journals which is for me non ethical.

I already came across several cases where I wasn't able to find the cited paper even years after publication of the paper with the citation.

Is it not necessary.

No, not necessary.

not necessary...

I consider the citation if necessary but I see that some say no

There is no such requirement whatsoever.

According to me, it is not necessary.

Of course it is not necessary. However, the are some editors who ask the authors to cite the papers from their journals, which in my opinion, is totally unethical.

No, not necessary!!!!!!!.

I've seen some editors of good Journals ask to add some literatures from the Journal just during revision process.

Negative -- it's unnecessary.