Both Jaishankar and Kantha are from 1977-batch IFS.
Significantly, both appointments come ahead of Prime Minister Manmohan Singh's visit to these countries. Singh is leaving for the US on September 25 and is expected to visit China next month.
Both the diplomats are expected to take up their respective assignment shortly, Ministry of External Affairs said today.
Jaishankar will replace Nirupama Rao.
Ashok Kantha is currently Secretary (East) in the MEA and has served in Malaysia and Sri Lanka among other postings.
However, the Prime Minister opted for the seniority and appointed Sujatha Singh as the Foreign Secretary.