They are not giving him billions. Trump wants repayment from Ukraine's resources. That was one of the reasons for Zelensky's visit to the US. To sign the contract.
Now China has cut off export of rare earth minerals to the US due to Trump's tariff war, the US is desperate to find new sources, and Ukraines just happens to have them in abundance.
Ukraine is getting nothing free from the US
Trump is playing both sides to try and make sure he can get at Ukraine's untapped riches.
As an aside. WTF is going on at the White House lately?
I wouldn't be surprised to see the Oval Office moved into a trailer home on the White House lawn soon.
All class, gravitas and dignity seem to have gone out the window.
President Trump, those $100 MAGA caps you are selling, really don't go well with your expensive tailored suits.