Taoiseach Mícheál Martin has embarked on his first non-EU trip since his leadership began last year, heading to New York for UN high-level week.
The week will see the Taoiseach address the UN General Assembly and chair a meeting of the Security Council, which Ireland is currently presiding over.
On Monday, he will meet with the new governor of New York Kathy Hochul before addressing the Council on Foreign Relations on Ireland’s UN priorities, the transatlantic relationship, and Brexit on Wednesday.
On Thursday, he will chair a meeting of the Security Council on the growing challenge of climate and security before, on Friday, delivering Ireland’s National Statement to the UN General Assembly.
Government sources said that the Taoiseach's overriding message to the assembly will be on the need for the UN to tackle climate change as a security risk.
He will tell the Security Council that conflict and diminishing resource availability due to climate change has "resulted in the breakdown of traditional systems for sharing resources and has led to violence between communities".
He will tell the council that it is "crucial that the Security Council considers the impact of climate change in its work to prevent and end conflict".
Ireland has placed climate and security as one of its priorities during its term on the UN Security Council, making the point that extreme weather events have displaced more than 24m people in recent years.
He will tell the UN that Ireland is to donate 1.3m vaccines to Covax, which will distribute them in the global south.
The Taoiseach's message to the UN will also touch on the country's commitment to peacekeeping missions, disarmament, and nuclear non-proliferation.
This will conclude in a Security Council meeting on the 25th anniversary of the signing of the Comprehensive Nuclear Test Ban Treaty.
Mr Martin's address will also touch on the ongoing violence in Afghanistan, Ethiopia, and the Middle East.
He will say that Ireland is "deeply concerned" by the situation in Ethiopia, particularly the lack of humanitarian access and the threat of famine, as well as reports of serious human rights violations.
He will say that Ireland is behind the "full implementation" of the Iranian nuclear deal, which Ireland is now a facilitator of at the UN.
The Taoiseach will also dedicate the building of the new Irish Arts Centre in the city and will take in a tour of NBC Studios at 30 Rockefeller Plaza.
Foreign Affairs Minister Simon Coveney will also be in New York this week as he is set to have a series of bilateral meetings with representatives linked to Ireland's presidency of the UN Security Council.