The decision was taken after the Bush administration received assurances in writing from the commission that such a step does not set a precedent and that the commission does not request "additional public testimony from any White House official, including Dr Rice," White House counsel Alberto Gonzales said in a letter to the panel.
Subject to the conditions, the president will agree "to the commission's request for Dr Rice to testify publicly regarding matters within the commission's statutory mandate," Gonzales's letter stated.
"The president recognises the truly unique and extraordinary circumstances underlying the commission's responsibility to prepare a detailed report on the facts," Gonzales added.
Congressional leaders, Gonzales noted, have already stated that this would not be a new precedent.
In addition, President George Bush and Vice-President Dick Cheney have agreed to a single joint private session with all 10 commissioners, with one commission staff member present to take notes.
The decision to have Rice testify was made in the wake of the publication of former White House counterterrorism chief Richard Clarke's book, in which he charges that the Bush administration was slow to act against the threat of al-Qaida.
Richard Clarke claims Bush was
slow to act on al-Qaida threat
Rice offered a rebuttal on Sunday to criticism by Clarke that President Bill Clinton "did something, and President Bush did nothing" before September 11 and that both "deserve a failing grade."
Rice responded: "I don't know what a sense of urgency - any greater than the one that we had - would have caused us to do differently."
Clarke testified before the commission last week.
Rice also said that she would not testify publicly as she has already delivered private testimony to the group.
Gonzales did not set a date for Rice's appearance but said: "We can schedule a time as soon as possible."