I would caution too many hands in the cookie jar ( negotiations ) could backfire because not only will it pull Ukraine in many directions but most will want a piece of the pie  (Ukraine)in some form or another. The more messy things can get if more are brought in. I would also be cautious who you take advice from as alterior motives are always at play. One good thing about the USA is they are not beholden to anyone. Make decisions based on what will be good for the country of Ukraine in the long term, never go for short term fast gratifiying solutions as they can cause more problems. 
The mining deal will definitely give Ukraine protection and better distribution, the USA will then also have to support infrastructure and ports simply because that is intertwined in transportation of said minerals. I am sure many countries are claiming support but I hazard to wonder what they all think they will get in return. I doubt any of those countries will tell Ukraine.