Deputy National Security Advisor Nehchal Sandhu, a former Intelligence Bureau chief, on Thursday tendered his resignation citing "personal reasons".
The resignation has been accepted by Prime Minister Narendra Modi with "regret", a PMO statement said.
Sandhu, a 1973 batch IPS officer of Bihar cadre, was appointed by the UPA government as OSD to the National Security Council rpt as OSD to the National Security Council on December 17, 2012 at the age of 61.
Sandhu, who joined as Deputy NSA on March 21 last year, was to have a fixed tenure of three years -- till December next year.
"Deputy National Security Advisor and Secretary, National Security Council Secretariat, resigned from his position with effect from July 31, 2014 for personal reasons," the statement said.
The prime minister accepted his resignation with "regret" and expressed appreciation for Sandhu's "outstanding service" to the country in a career spanning over 40 years - as a police officer, Director of Intelligence Bureau and Deputy National Security Advisor.