Mrs Clinton said she had been to NI more than her husband
Hillary Clinton has defended her role in the Northern Ireland peace process and accused Barack Obama of "nitpicking".
The New York senator has cited her involvement as an example of her foreign policy credentials.
Mrs Clinton visited Northern Ireland several times while her husband Bill was US president.
"I actually went to Belfast more than Bill did as part of what I was doing to help the process," she said.
Bill Clinton took a keen interest in Northern Ireland affairs and was involved in the negotiations which led to 1998's Good Friday Agreement.
Mrs Clinton added that she continues to be engaged with leaders from Northern Ireland and questioned whether Mr Obama could say the same.
"Just this week I was called to meet with the secretary of state for Northern Ireland," said Mrs Clinton.
"This is something I do on a regular basis, to get an update about where the process is now.
"I understand the desire of my opponent to try to nitpick and bring people out to say things, but I think the record is very clear and one can, you know, look at many different sources."
Former SDLP leader John Hume has come out in support of Mrs Clinton over the issue.
"I am quite surprised that anyone would suggest that Hillary Clinton did not perform important foreign policy work as first lady," he said.
However, former UUP leader David Trimble has likened her role to that of a "cheerleader".
"I don't know there was much she did apart from accompanying Bill going around," he said.