Former foreign secretary J N Dixit was on Wednesday appointed national security adviser to Prime Minister Dr Manmohan Singh.
Dixit will replace Brajesh Mishra, who resigned on
Tuesday.
Dixit, who held several key positions in the Indian Foreign Service, including high commissioner to Pakistan and Sri Lanka, is expected to take over from Mishra shortly.
Dixit was instrumental in formulating the Congress agenda on defence, security and foreign policy before the Lok Sabh election.
He is currently vice-chairman of the foreign affairs department of the All India Congress Committee.