The King is set to visit Northern Ireland on Tuesday.
Charles and Camilla, the Queen Consort, will travel to Hillsborough Castle and Belfast for several engagements including a memorial service.
Mr Martin said: “I will be going to Belfast tomorrow.
“The President and I we have been invited to the memorial service and we will go to that tomorrow.”
Mr Martin was speaking at the Fianna Fail party think-in in Mullingar.
Mr Higgins’ wife Sabina Higgins and Minister for Foreign Affairs and Defence Simon Coveney will also attend the memorial service at St Anne’s Cathedral.
The trip to Northern Ireland by Charles and Camilla will follow a visit to Scotland on Monday, with a trip to Wales planned for later in the week.
A significant security operation is under way in the Co Down village of Hillsborough ahead of the royal visit.
People continue to congregate at Hillsborough Castle, the royal residence in Northern Ireland, where a large number of floral tributes have been laid.