The Covid-19 pandemic has taken its toll on society, particularly on those who have lost loved ones to the virus, the Taoiseach has said.
Micheál Martin said the pandemic had impacted "every community in every country and indeed our entire way of life".
Mr Martin made the comments ahead of his address at the 75th annual meeting of the United Nations General Assembly on Saturday.
This year's General Assembly is taking place remotely, with heads of state and government of 196 countries delivering their statements via pre-recorded video messages.
"This year's United Nations General Assembly is meeting in the shadow of Covid-19," Mr Martin said.
"The virtual format reminds us all of the need to keep our distance and limit our contacts; practices which are so simple but which have the power to help us arrest this deadly virus.
"This pandemic has impacted every community in every country, and indeed our entire way of life.
"It has taken its toll on society, particularly those who have lost loved ones, or who have contracted the virus themselves and are suffering from its lasting after-effects."
But he said the pandemic had also brought out an "incredible motivation for people to work together to combat this fatal virus".
"The pandemic reminds us that multilateral responses to global challenges remain essential.
"In an interconnected and interdependent world, even the strongest cannot succeed alone," the Taoiseach said.
Ireland is set to take up a seat on the UN Security Council next year.
"We join the Council with firm principles and clear priorities - building peace, strengthening prevention and ensuring accountability," he said.
"These are at the heart of the Council's mandate.
"Ireland has a strong and proud record of UN peacekeeping and I am confident that we will be to the fore in promoting the core values of building and maintaining international peace and security."