I-864, I-864A, or I-864EZ affidavit, i dont know which one to use. help me, I am a citizen that is bringing 2 child(my biological children from a previous marriage, born under marriage). i have the financial requirements and i will use only my income for this, once they enter the country i will apply for a passport for them in accordance with th child citizen act.

let me know please which one is the correct affidavit form. any help will be appreciate.

I-864 and I-864 EZ are for sole sponsorship without a co sponsor.
I-864 EZ is just for peeps that use salary only and no assets to meet the requirements.
!-864A is for the co sponsor if petitioner has to use one.

Sounds like you can register your kids at the embassy of the country they were born if they are under 18.
They can get a US passport there and no need to go thru immigration.

I became citizen after they were born, so they can't.

Which applicants for family-based immigrant visas do not need the I-864 Affidavit of Support?

The following applicants for family immigrant visas do not need an I-864.

Biological (natural-born) children of American citizens (IR-2 immigrant visa category) who will enter the United States when under the age of eighteen and will automatically acquire American citizenship

according to this they don't need this affidavit, but my confusion is why they send me instruction to download this form and send it back to them, when it says clearly, they don't need it.

Kids aren't IR-2
Are you already in the process of bringing them to the US. IF so! K2s or did you file I-130s for them?

i think you can use the I-864w
thats a waiver