rescind the agreement(Rescission refers to the right of one party to "rescind" a contract due to a breach or some other action on the part of the other party. Rescinding a contract means dissolving and putting the parties in the position they were in before entering into the agreement. 4uzhoj)
repudiate(Law refuse to fulfil or discharge (an agreement, obligation, or debt): breach of a condition gives the other party the right to repudiate a contract. COED Alexander Demidov)
repudiate a contract(Law refuse to fulfil or discharge (an agreement, obligation, or debt): breach of a condition gives the other party the right to repudiate a contract. NOED Alexander Demidov)