Absolutely. The US citizen spouse can, at their discretion, revoke the I-130 and/or I-864 at any time before the visa is issued by contacting USCIS, NVC, and/or the Consulate in writing. That will terminate the case. This is irrevocable. Once the visa is issued, it becomes more difficult as the consulate would have to void the printed visa. If CPB or the airlines are informed of a voided visa, they can then stop the foreign spouse from traveling and/or entering the US.
Once an immigrant spousal visa holder (CR-1 or IR-1) enters the US with a valid visa, then the visa holder automatically becomes a Green Card holder at that point. At that point, it would be extremely difficult to get USCIS to intervene short of proof of fraud. (Remember, obtaining a spousal visa requires a great deal of bona fide marriage proof from the US citizen as well as the immigrant)
If the immigrant enters the US via a CR-1, then the US citizen can refuse to participate in the joint I-751....2 years later, making it difficult (but still possible) for the immigrant to obtain a 10 year Green card.