Queen Elizabeth says Britain will be represented at events to mark the creation of the Irish Free State.
She made the comments at a State banquet in honour of President Michael D Higgins at Windsor Castle last night.
Day two of the President's State visit will include a meeting today with the British Prime Minister at Downing Street.
From London - our News Correspondent Fergal O'Brien reports:
The Queen and Michael D Higgins exchanged gifts at the State Banquet last night.
Queen Elizabeth gave the President a pair of photogrphs of herself and the Duke of Edinburgh in silver frames.
He also received a copy of Dubliners by James Joyce, which had been bound and boxed by the Windsor bindery.
Mrs Sabina Higgins was given a small engine turned box with gold cypher by William and Son.
President Higgins gave the queen a gift of a table-sized dimpled bronze statue of Arkle, the most feted steeplechaser of the post-war era, with jockey Pat Taaffe on board - it was sculpted by Emma MacDermott.
At the banquet the Queen's white silk and lace evening dress by Angela Kelly was the official dress of her diamond jubilee in 2012.
The dress worn by Sabina Higgins was commissioned from Louise Kennedy, especially for the ocassion - in St Patricks blue, it reflected the official colour used in the Presidents Standard, and was covered with myriads of crystal stones reflecting the Connemara landscape.
