S Jaishankar, India's ambassador to the United States, has been appointed the new foreign secretary.
Jaishankar, a 1977-batch IFS officer, will serve in his new role for two years. He was scheduled to retire on January 31, but will now succeed foreign secretary Sujatha Singh, who has served in this position for one and a half years and demits office on January 31 instead of as scheduled in August.
Jaishankar is considered the architect of the Indo-US nuclear deal of 2008, and the man behind the recent breakthrough on its operationalisation.
He was previously the envoy to China before being appointed as India's ambassador to the US.
He is said to be the person behind US President Barack Obama's first-off-the-blocks congratulatory call to Prime Minister Narendra Modi after the Lok Sabha poll results were declared in May.
Jaishankar is also said to have been instrumental in reversing the US no-visa policy on Modi, who first met him during a visit to China in 2011.
The two met late Tuesday night.
The announcement was made following a meeting of the Appointments Committee of the Cabinet chaired by the PM.
"Appointment of S Jaishankar, IFS batch 1977, as Foreign Secretary vice MS Sujatha Singh with a tenure of two years from the date of assumption of charge or until further orders, whichever is earlier, in keeping with the provisions of FR-56(D)," a late-night announcement said on Wednesday.
The official statement added the tenure of Singh, who took over as the third woman foreign secretary in August 2013, was "curtailed" with immediate effect.
Some reports said Singh was not given any other assignment by the government.