After signing the visitors' book at the Taj Mahal Palace and Tower Hotel, the first halt after he arrived here just before 1 p.m., Obama described Mumbai as a "resilient" city.
In his brief speech at the hotel, Obama mentioned by name Kang, who he said risked his life to save the hotel guests after it came under attack by a group from among the 10 Pakistani terrorists who went on a killing spree in Mumbai in November 2008.
Kang lost his wife Niti and their sons Uday, 14, and Samar, 5, in the sixth floor of the Heritage wing of the Taj hotel.
Despite losing his family, Kang continued to supervise rescue operations at the hotel and helped numerous guests to escape.
The president also praised Sandra Samuel, the Indian nanny "who braved bullets to save the baby" of the rabbi couple.
Samuel worked for Gavriel and Rivka Holtzberg at the Chabad house in Mumbai which was also attacked by the terrorists. She spirited their son Moshe, who was two years old then, away to safety during the attack.
Obama was full of praise for the resilience of the people of the "dynamic and historical city" of Mumbai.
He said his presence at the Taj Hotel, where he is staying overnight, was a "clear message" to the people. "The Taj is a symbol of the strength and resilience of the people" of Mumbai, he said.