Unrwa's plan, unveiled in Jordan on Tuesday, outlines specific mechanisms for providing food, shelter, health care and education to Gaza's population.
The Gaza Strip suffered heavy infrastructure damage during last month's 23-day conflict in which more than 1,300 Palestinians and 13 Israelis were killed.
Israel says the war was meant to dismantle Hamas's ability to fire rockets into southern Israel from Gaza.
Egyptian officials have in recent weeks sought to secure a long-term ceasefire deal between Hamas and Israel.
However, negotiations stalled on Wednesday when the Israeli security cabinet rejected an agreement that did not include the release of Gilad Shalit, an Israeli soldier captured by Palestinian fighters in 2006.