US President Barack Obama has called Joko Widodo to congratulate him on his victory in Indonesia's "free and fair" presidential elections, the White House said Wednesday.

During the conversation on Tuesday night, "President Obama told President-elect Widodo that he looks forward to meeting him at the earliest opportunity and to working with him to deepen the US-Indonesia partnership, expand ties between our two peoples, and promote our shared objectives in Asia and around the world," the White House said.

After a lengthy vote count, Widodo -- the reform-minded governor of Jakarta -- was on Tuesday declared the winner of the July 9 election by more than six percentage points.

Rival Prabowo Subianto, a retired general, has decided to challenge the results in the courts, his campaign team said Wednesday.

The White House said Obama "noted that through this free and fair election, the people of Indonesia have once again shown their commitment to democracy."

"The president reaffirmed that the United States deeply values the close and cooperative relationship with Indonesia, including the US-Indonesia Comprehensive Partnership, which has strengthened our bilateral ties and facilitated deeper cooperation on common regional and global challenges."

The southeast Asian nation is the world's third largest democracy and fourth most populous country.