UN Secretary-General Antonio Guterres on Saturday reiterated his call for irreversible progress toward a two-state solution, in a message on the International Day of Solidarity with the Palestinian People.

This year's International Day of Solidarity with the Palestinian People, which is observed annually on Nov. 29, comes after two years of horrific suffering in Gaza, and the start of a much-needed ceasefire, Guterres said.

Noting that survivors are mourning the deaths of tens of thousands of friends and family; hunger, disease and trauma run rampant; injustice also continues in the occupied West Bank, including East Jerusalem; and hundreds of humanitarians have been killed, the UN chief said: "In so many ways, this tragedy has tested the norms and laws that have guided the international community for generations."

"The killing of so many civilians, the repeated displacement of an entire population and the obstruction of humanitarian aid should never be acceptable under any circumstances," he underscored.

As the recent ceasefire offers "a glimmer of hope," "it is now vital that all parties respect it fully and work in good faith towards solutions that restore and uphold international law," the UN chief stressed, adding that lifesaving humanitarian aid must be allowed to enter Gaza at scale, and the international community must continue to stand firmly with UNRWA, the UN relief agency for Palestinians.

"I repeat my call for an end to the unlawful occupation of the Palestinian Territory ... and for irreversible progress towards a two-State solution, in line with international law and relevant UN resolutions, with Israel and Palestine living side by side in peace and security within their secure and recognized borders, on the basis of pre-1967 lines, with Jerusalem as the capital of both States," Guterres said.

"Let us stand in solidarity with their rights to dignity, justice and self-determination -- and work together to build a peaceful future for all," the UN secretary-general said.

In 1977, the UN General Assembly called for the annual observance of Nov. 29 as the International Day of Solidarity with the Palestinian People. On that day in 1947, the General Assembly adopted the resolution on the partition of Palestine.