The $250m will ugrade Kolwezi to Luau (and other infrastructure on the Angola side.
Only $100-150m is for DRC, the rest for Angola).
This part functions OK but needs to be upgraded to handle far more freight.
For this new line in Zambia to Lobito, I am not sure how the US and EU will fund it. I believe it will be loans secured by the concession.
Also, from the EU statement, they want to make sure this is a "sustainable" investment- so the line must help increase trade, agriculture, tech transfer, clean energy production, etc.
US wants this too but the EU has laws that require investments be "sustainable" and "inclusive".