The Taoiseach has said that when the true horrors of Gaza "are finally and fully revealed, it will shame the world".
During his address to the United Nations General Assembly in New York, Micheál Martin said the international community has "failed Palestine" and criticised last year's Gaza peace plan, saying that it has not "changed the reality on the ground".
"When the full truth of what has happened - what is still happening - in Gaza is finally known, when the evidence is gathered, when the testimonies are heard, when the true horrors are finally and fully revealed, it will shame the world," he said as the audience applauded.
Mr Martin also hit out at attempts to make the prospect of a two-state solution "impossible".
"This is not some mad conspiracy theory," he said.
"It is the stated intent of the Prime Minister of Israel, who said clearly that 'we are going to fulfil our promise that there will be no Palestinian state. This place belongs to us,' as he permitted the E1 settlement development in East Jerusalem."
The Taoiseach said that most countries have taken steps to push back against "the illegal and violent settler occupation of Palestinian land in the West Bank", but he said time is running out.
"Violent settlers continue to act with near-total impunity, while Palestinian communities face a sustained campaign of displacement and destruction - amounting to ethnic cleansing," he said.
Israeli Prime Minister Benjamin Netanyahu also spoke last night, after a mix of cheers, boos and a mass walkout, downplaying settler violence and claiming that it was the work of "a handful of young juvenile delinquents".
Watch the Taoiseach's full address to the United Nations General Assembly:
Iran must never have a nuclear weapon - Taoiseach
In front of delegates, Micheál Martin said that the only viable solution to the decades of conflict, misery and wasted human lives is for a State of Palestine and a State of Israel to live side-by-side in peace, security and dignity.
He also called on the United States and Iran to get back around the negotiation table to solve the conflict.
"We need to get back to meaningful, good-faith negotiations by all sides," he said.
"If we are to build greater stability, Iran must never have a nuclear weapon. Iran's destabilising influence across the region must cease," he said.
Mr Martin also used his speech to call on the international community not to walk away from bodies like the United Nations, and criticised efforts to undermine the International Criminal Court.
He reminded the audience of what the UN could achieve, including reducing poverty and security.
However, the Taoiseach said the world is not staying the course when it comes to peace and security, human rights and development.
Russia's war in Ukraine was also a dominant theme in the Taoiseach's speech.
"Russia could halt its brutal attacks at any time. Yet it refuses to do so," he said.
"Russia's actions have already had direct global impact, including increased food and energy costs."
Mr Martin also highlighted the war in Sudan, paid tribute to the peacekeepers ahead of ending of the UNIFIL mission in Lebanon, spoke about women's rights in Afghanistan and expressed fears for the LGBTQI+ community.
He also pitched for Ireland to be part of the UN's Human Rights Council for the 2027–2029 term.
