Air strikes, ground offensives underway in densely populated camps, damage to homes, water pipes and power networks, the official denounced on Twitter.
Hastings noted that thousands of civilians have been displaced as a result of the operations in the Jenin refugee camp.
Most of the residents do not have electricity and drinking water, said the coordinator, who called to focus the most immediate work on the care of the wounded and emergency assistance to the population.
Also on Twitter, Hastings expressed alarm at the size of the Israeli attacks on Monday.
Shortly afterwards, the UN special envoy for the Middle East peace process, Tor Wennesland, called for a de-escalation of violence.
I am in direct contact with all relevant parties to urgently de-escalate violence and ensure humanitarian access and the delivery of necessary medical and other supplies, he stressed.
Wennesland also urged ensuring the protection of the Palestinian civilian population.