I don’t know how the US can “kill” this project if we are not financing it. The USA doesn’t control the whole Mediterranean. They should build it anyway and dare the US to try and stop them! Bad optics for Biden if he tried!
What leverage does Biden have other than stopping weapon sales to Israel?
My guess is that it boils down to the US insuring international maritime law: In this case, freedom from harassment of vessels involved in the project by Turkish "gunboat diplomacy". Note the harassment of the Italian survey ship by the Turks. Like it or not, only the US has the might to enforce, in effect, "no funny business" (sabotage / harassment) by "anybody" (ie., the Turks) and most importantly, be a credible deterrent.
Well, that very last if we had an actual President.