The UN Secretary-General Ban Ki-moon on Tuesday criticised Israel's blockade of the Gaza Strip, describing it as "collective punishment".
The UN chief made the comment on his final trip to Palestinian territories before his tenure expires.
Ban said the blockade of the Palestinian enclave "suffocates its people, stifles its economy and impedes reconstruction efforts."
"It is a collective punishment for which there must be accountability," he said.
"We must speak openly about the unacceptable hardships faced by the people of Gaza in light of the humiliation, occupation and siege, as well as the division between the Gaza Strip and the West Bank," Ban added.
The outgoing head of the UN also held talks with Israeli Prime Minister Benjamin Netanyahu in Jerusalem and Palestinian President Mahmoud Abbas in Ramallah.
Ban condemned a recent wave of Palestinian knife, gun and car-ramming attacks since October, which he called "terrorism", but said the causes of the violence should be addressed.
"We cannot ignore key underlying causes of violence: growing Palestinian anger, the paralysis of the peace process, the nearly a half-century of occupation," Ban said alongside Netanyahu.
He also urged Netanyahu to take "courageous steps" toward peace in order "to prevent a one-state reality or perpetual conflict that is incompatible with realising the national aspirations of the Israelis and Palestinian people."
Later in the evening Ban met Abbas at the Palestinian leader's Ramallah headquarters and again spoke of the difficulties Palestinians face.
"I'm aware that many Palestinians question the feasibility of reaching a just and lasting peace with Israel. They hear talk of peace but they see violence," he said.
"They still live a life of checkpoints, permits, blockade, demolitions and profound economic hardships faced with growing indignities and the humiliating occupation that will soon enter its 50th year."
Abbas said Palestinians seek peace based on a two-state solution and called for "international protection" for his people.