where to buy a brand new iphone with dual sim cards slot in the usa ??

iPhone XS and later are dual-capable, with SIM and eSIM: Using Dual SIM with an eSIM - Apple Support

In China mainland, Hong Kong, and Macao, iPhone 12, iPhone 12 Pro, iPhone 12 Pro Max, iPhone 11, iPhone 11 Pro, iPhone 11 Pro Max, iPhone XS Max, and iPhone XR feature Dual SIM with two nano-SIM cards: Using Dual SIM with two nano-SIM cards - Apple Support

Any dual-SIM iPhone model you might find available in the US is grey market, and with no local warranty.

No, unless you have a friend in China who could buy it and ship it to you. But there are 2 major downsides:

1. It would have no warranty, and if it needed repair even out of warranty Apple would not repair it except in China
2. It will come with Chinese government spyware and access restrictions

aadel1 wrote:

Thanks for the reply,..There any way to buy an iPhone with two sim slots from China or Hong Kong ?!

There is no official means and no Apple-sanctioned means to do that. You might be able to acquire one through a grey market purchase as was mentioned (and do your own research and your own due diligence, etc), or by visiting and buying in those countries and regions and then importing it yourself.

Warranty coverage will be problematic in either (any) case.

Nowhere. Dual physical SIM phones are only sold in China.

Thanks for the reply,..There any way to buy an iPhone with two sim slots from China or Hong Kong ?!

To get a phone from China or Hong Kong, you would have to go to China or Hong Kong.