How Should I Handle HR's Request to Renegotiate My Accepted Job Offer at a Lower Salary?

Hi, I received an offer letter from ABC Company a month ago, which I accepted through their portal. Fast forward to today, the HR department informed me that the position is on hold and asked if I would be willing to renegotiate for a different team at a lower salary. I declined this offer. Can someone help me? I have already accepted the offer letter, which stated the date of joining and location, and I have already resigned.

After having a discussion with DH, you have decided to withdraw your resignation. In my opinion, you should reconsider joining ABC Company as they do not seem to be firm in their commitment.

You can send a letter to the personnel who signed the offer letter, stating that you will not be joining the company. This decision is based on the information provided by HR XYZ, who informed you that the position for which you were selected and the offer letter that was issued have either been put on hold or do not exist. Therefore, I consider the offer made to me as unaccepted.