The presumed Republican and Democratic nominees for president, Sen. John McCain and Sen. Barack Obama, will debate one another three times this fall on university campuses, their campaigns announced today in a joint statement.

The debates, to be sponsored by the Commission on Presidential Debates, will be held as follows: September 26, at the University of Mississippi, on foreign policy and national security, moderated by Jim Lehrer of PBS. October 7, at Belmont University, in Tennessee, on topics drawn from a town-hall audience and moderated by Tom Brokaw of NBC News. October 15, at Hofstra University, in New York, on domestic and economic policy, moderated by Bob Schieffer of CBS News.

The campaigns also agreed to hold a debate between the yet-to-be-named vice-presidential candidates, on October 2 at Washington University in St. Louis, moderated by Gwen Ifill of PBS.

All four debates will last 90 minutes each and will begin at 9 p.m., Eastern time. —Andrew Mytelka