"DMK is part of the UPA. Therefore, we will support the one who is fielded on its behalf," DMK president M Karunanidhi told reporters here.
The DMK chief had recently said his party would back Union Finance Minister Pranab Mukherjee for the top post.
Incumbent Pratibha Patil's tenure ends on July 25. AIADMK and BJD have jointly announced backing NCP leader P A Sangma's candidature for the Presidency.