Micheal Martin said King Charles will continue to “underpin the peace and good relations” between Ireland and the UK.
Mr Martin said King Charles is “very familiar with Ireland” and has a “keen interest” in Irish affairs, having previously met him and his wife Queen Consort Camilla several times on his visits to Ireland.
When asked if he would invite him to visit Ireland, Mr Martin said issuing the invitation would be a “matter for the President”.
“He is always welcome to Ireland,” he said.
“I’ve no doubt that he will continue that interest in Ireland, particularly his interest in climate change, diversity, wildlife and i do foresee opportunities to dovetail, if you like, that interest that he has in terms of some of the initiatives that we are taking in terms of preserving biodiversity into the future.
He said King Charles will continue to “underpin the peace and good relations” between Ireland and the UK.
However, Mr Martin declined to confirm if he will travel to London for Queen Elizabeth’s funeral.
“The funeral arrangements will be a matter for the authorities in the United Kingdom. Suffice to say that we as a Government would be pretty clear in terms of our expressions of sympathies to the British people.”
The Taoiseach said her most “enduring legacy” will be her visit to Ireland in 2011, where she famously made a speech in Dublin Castle and spoke Irish.
“It’s a visit that will never be forgotten and I think in the context of all that has gone on between Britain and Ireland over centuries, it definitely closed one chapter and opened up another.
“The head of State of the UK coming to Ireland, it represented the crowning moment, if you like, all that had gone on in terms of peace building and building a new political order,” he said.
He said she ruled for 70 years through an “extraordinary sweep of history” which showed “the importance of the fundamentals of service, duty, consistency of approach”.
“In the context of the British people, we sympathise with them, we understand the enormous change it represents, in terms of her passing and the impact she has had on their lives over such a long, long period of time,” he said.
Mr Martin was speaking at the launch of 31 social houses in Bray, Co Wicklow.