Does USA allow multiple naturalisation (i.e passports from two different countries (UK & USA) in addition to birth citizenshi)?


Please I need your kind advice on the following issue.

I am a citicizen from another country, I am just qualified to apply for British Naturalisation now having spent more than 10 years in the UK (and I have got UK ILR for more than 12 months). I also have pending settlement visa application with USA (through USA citizen brother that filed a settlement petition/application/sponsorship for me).


(a) Is it legal to have three passports (i.e (1) birth citizenship, (2) UK by naturalisation and (3) later, USA by naturalisation via green card/settlement visa)?

(b) If I submit my UK naturalisation application now and get UK passport before obtaining USA settlement visa/green card, will I be able to still legally obtain USA passport in future?

Thanks in advance.