At the council, Tewari will focus on developing programmes aimed at strengthening US-India ties, a statement released by his office said.
A senior counsel practising in the Supreme Court, Tewari previously served as a Member of Parliament from Ludhiana and is currently the national spokesperson of the Congress party.
"South Asia is a region with complex traditional and human security challenges and is home to almost two billion people. As the new administration takes shape, I look forward to working with the council's South Asia Center in developing programmes on how the new administration can best engage with the region to strengthen key relationships," Tewari said as per the statement.