January 20, 2021: US President Joe Biden speaks during his inauguration on the West Front of the US Capitol in Washington, DC.Getty Images

Joe Biden, a proud Irish American, was officially sworn in as the 46th President of the United States today, January 20.

Michael D. Higgins, the President of Ireland, shared a letter issued to the new President of the United States.

President Higgins, who said he and his wife Sabina look forward to again welcoming Biden to Ireland, wrote in part: "The US has been a true friend to Ireland in so many ways.

"Your own friendship and support for so many years has been invaluable. Ireland, of course, has made its most valuable contribution to your great land by providing so many of our daughters and sons. The descendants of some turned out to be rather fine Presidents!"

Taoiseach Micheál Martin congratulated both President Biden and Vice President Harris upon their inauguration.

Noting Joe Biden's Irish ancestry, the Taoiseach said in a statement: “As he [Biden] takes the oath-of-office, I know that President Biden will feel the weight of history – the presence of his Irish ancestors who left Mayo and Louth in famine times in search of life and hope.

“He will remember their descendants’ hard struggle as they made their way in and their contribution to the United States. It is the story of Irish-America.

“I hope he will also be conscious of the great pride we in Ireland take in his immense achievement. He is one of us, part of our global family."

Simon Coveney, Ireland's Minister for Foreign Affairs, said "Ireland takes great pride" in Biden's inauguration:

Daniel Mulhall, Ireland’s Ambassador to the US, was on hand for the inauguration events in Washington, DC today:

Arlene Foster, the First Minister of Northern Ireland, offered her congratulations to both President Biden and Vice President Harris:

Michelle O’Neill, the Deputy First Minister of Northern Ireland, sent her best wishes to Biden and Harris: