India's concerns on terrorism emanating from Pakistan will top the agenda of talks as External Affairs Minister S.M. Krishna heads for Islamabad Friday to meet his Pakistan counterpart Hina Rabbani Khar. The Indian side has made it clear that terrorism, and particularly the Mumbai terror attack, would remain a "core issue" as both sides review the second round of the dialogue process, revived in February 2011 after a long hiatus following the 26/11 Mumbai terror attack.