The United Nations launched an appeal Monday for $547 million (524 million euros) to help 1.6 million people in the Palestinian territories in 2017.
The response covers 1.1 million residents of the Gaza Strip, which has been under an Israeli blockade for the past decade, and half a million people in the occupied West Bank.
The most recent conflict between Israel and Gaza ended in August 2014 but Israel has maintained tight restrictions on the enclave, while Egypt has also closed its border.
The United Nations has warned that tiny but densely populated coastal enclave could become uninhabitable by 2020 if current trends continue.
"Needs in Gaza remain particularly acute and humanitarian services provided by the international community remain a lifeline," said Robert Piper, UN humanitarian coordinator for the Palestinian territories, in a letter accompanying the launch.
Politically there has been few positive trends in 2016, with plans for a unity government stumbling amid deepening divisions between rival Palestinian factions.
Attempts to encourage new peace negotiations between Israel and the Palestinian leadership, stalled since 2014, have also failed.
Piper said in a separate statement that without political reform and a meaningful peace process, international aid was "just trying to buy time".
"This humanitarian response must be coupled with bold political action," he said.