"I got a letter from the FAI on Monday when I arrived at the training ground and it confirmed that I had been called up," he told the clubs official website.
"I had to look at it twice because it's what I've been working for.
"All my life, I've wanted to play for my country and I didn't really believe it when I read it. I'm obviously delighted and my mobile phone was ringing all day yesterday.
"There has been speculation about me being in the squad, but you never know.
"I've only really been playing league football for three months since the start of the season, and things could not have gone much better for me at Sunderland."