Sure. Fine. That's an easy negotiation. Ukraine is under duress. Promise whatever it takes to get the defense aid necessary to your survival.
Then, when the war is over, break your promises (can be done either politely or rudely). The polite way is to hope that you have a new, non-evil US regime to approach and say "hey, it would be economically crippling for us to give all that shit to you, how about you let us out of some key elements of the deal," and have an agreed extrication from the truly burdensome elements. The rude way is just to say "nope, fuck off, we're not letting your interests into the country." Either one works. If we get pissed off and threaten to sanction Ukraine because they aren't sticking with the "deal" we forced them into....who do you think will join us? Nobody.
So, sure. Promise the Regime they can build Trumpland amusement parks in every Ukrainian city, and that they'll send tribute of $100 million a month in Trump meme coins as soon as the war is over. Whatever. It's a deal that isn't worth more than the paper it's printed on (and, if it's like the recent deal signed at the G7 summit.....it's literally JUST the paper and signature).