GENEVA - Gaza will need a new "Marshall Plan" to recover from the conflict between Israel and Hamas, a UN trade body official said on Thursday, adding that the damage from the conflict so far amounted to around $20 billion.

Speaking on the sidelines of a UN meeting in Geneva, Richard Kozul-Wright, a director at trade body UNCTAD, said the damage was already four times that endured in Gaza during the seven-week war in 2014.

"We are talking about around $20 billion if it stops now," he said.

Kozul-Wright said the estimate was based on satellite images and other information and that a more precise estimate would require researchers to enter Gaza.

The reconstruction will require a new "Marshall Plan", he said, referring to the US plan for Europe's economic recovery after World War Two.

UNCTAD already said in a report last month that it could take until the closing years of the century for Gaza's economy to regain its pre-conflict size if hostilities in the Palestinian enclave were to cease immediately.