That was quick
Tusk spokesman: "Withdrawal agreement is and remains best and only way to ensure an orderly withdrawal of the UK from the EU. The backstop is part of the Withdrawal Agreement, and the Withdrawal Agreement is not open for re-negotiation."
May is going to go to Macron and Merkel and beg for something. She pushed for this so she must believe there is a way to renegotiate.
The EU spokesman also said they stand ready to consider a delay.