The Taoiseach Micheál Martin will address the United Nations on Thursday evening as Ireland attends a contentious meeting of the body's Security Council in New York.
Russian president Vladimir Putin's promise to mobilise more Russian troops for the war in Ukraine has cast a cloud over world leaders meeting at the UN General Assembly.
With the Russian military suffering huge losses in personnel and territory in Ukraine, Putin has ordered a partial mobilisation of troops, the first time this has happened since the Second World War.
Last night an emergency meeting of EU foreign ministers was held on the margins of the summit.
On Thursday morning, Minister for Foreign Affairs Simon Coveney will speak for Ireland at the UN Security Council.
It's the first time since the outbreak of the war that the foreign ministers of the five permanent members of the UN Security Council will attend in person.
This means Mr Coveney will be sitting across from Russian foreign minister Sergei Lavrov when he gives a speech which is expected to be highly critical of his country's actions.
Putin's speech is being seen as the most significant development in the war since it began on February 24th.
Many foreign leaders feel it is an act of desperation.