Does my UK partner need a CNI to marry me in the US and return?

Basically my current partner and I are looking at all our options there is a very specific timeline we are trying to follow and we’d like the cheapest/fastest route for me to live in the UK.

I was blindsided by the cost, bureaucracy and wait times required in the uk regarding marriage on top of the visa process.

My partner went to the register today to ask questions and they mentioned he would need a Certificate of No Impediment to show in America but searching around online it said a CNI is not required for marriage in America. Would they require it for the marriage visa?

Thanks for any help!