I don't think "deal" is the best choice of word here because it does somehow imply that they are being sent in return for payment, which I don't imagine to be the case.
However, literally speaking, "a deal worth XXX" means "an arrangement with a value of XXX", so it doesn't necessarily refer to the payment, only to the value of the tanks. If it said "a deal worth XXX to the US", it would necessarily mean that the US was receiving payment, but that it not the case here.
However, I agree that, generally speaking, if you say Company X and Company Y have completed a deal worth XXX dollars", you assume that one of them is selling something to the other in return for payment.