RSS chief Mohan Bhagwat on Tuesday said India has lost "one of its greatest sons" in the death of former president A.P.J. Abdul Kalam.
In a statement along with his colleague Suresh Joshi, Bhagwat said Kalam's 83 years of life was "a tale of extraordinary courage, determination, perseverance and the desire to excel".
Bhagwat said that as a scientist, Kalam made seminal contributions to India's defence preparedness.
"As a statesman, (he) made Bharat proud by enhancing the prestige of the president's office through his exemplary conduct of affairs."
The statement said Kalam's death in Shillong on Monday was "an unsurmountable loss" to the country.