Saudi Arabia on Wednesday hosted the first meeting of a new "international alliance" to press for the establishment of a Palestinian state.
Unveiled last month on the sidelines of the UN General Assembly, the "International Alliance to Implement the Two-State Solution" brings together nations from the Middle East, Europe and beyond.
Saudi Foreign Minister Prince Faisal bin Farhan said nearly 90 "states and international organisations" were taking part in the two-day meeting in Riyadh.
"A genocide is happening with the goal of evicting the Palestinian people from their land, which Saudi Arabia rejects," he said, describing the humanitarian situation as "catastrophic" and denouncing the "complete blockade" of northern Gaza.
The Riyadh meeting was expected to focus on humanitarian access, the embattled UN agency for Palestinian refugees and measures to advance a two-state solution, diplomats said.
The European Union was set to be represented by Sven Koopmans, the special representative for the Middle East peace process, diplomats said.
The United States, Israel's most important military backer, sent Hady Amr, the State Department's special representative for Palestinian affairs.
The Gaza war has revived talk of a "two-state solution" in which Israeli and Palestinian states would live in peace side by side, though analysts say the goal seems more unattainable than ever.
The hard-right Israeli government of Prime Minister Benjamin Netanyahu remains implacably opposed to Palestinian statehood.
Saudi Arabia, the world's biggest oil exporter and custodian of Islam's two holiest sites, paused US-brokered talks on recognising Israel after the Gaza war broke out between Palestinian militants Hamas and Israel.
In September, the kingdom's de facto ruler, Crown Prince Mohammed bin Salman, said an "independent Palestinian state" was a condition for normalisation.
Prince Faisal reiterated that position on Wednesday.
Ireland, Norway and Spain announced their recognition of a Palestinian state in May, prompting an angry response from Israel.
Slovenia soon joined them, bringing the number of countries that recognise a Palestinian state to 146 out of the 193 UN member states.
The Gaza war was triggered by Hamas's unprecedented attack on southern Israel on October 7 last year which resulted in the deaths of 1,206 people, mostly civilians, according to an AFP tally of Israeli official figures.
Israel's retaliatory offensive has killed at least 43,061 Palestinians in Gaza, most of them civilians, according to figures from the Hamas-run territory's health ministry which the United Nations considers reliable.