Amazon Brand registry. EU and USA

Hello

We have reseller authorisation from the company to sell their product within the UK and Europe on Amazon in these jurisdictions. However they currently have an other reseller in the US selling their products on Amazon US.

The reseller selling their products on Amazon US set up the company's Amazon brand registry and so the company does not own the current brand registry set up on its name.

How can we set up a brand registry for Europe and Uk.

We can apply for the Uk&EU Trademark, and then apply for the Brand Registry under my seller account however l fear Amazon Brand Registry will deny due to this brand name already existing on Amazon.

Should we request access from the reseller in the US to use this brand in EU ?

What will then happen with the listings as we will be selling the same products?