The resignation has been accepted by Prime Minister Narendra Modi with "regret", a PMO statement said here today.
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.
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.