Widodo took the oath Monday before the Sultan of Brunei; US Secretary of State John Kerry; the prime ministers of Australia, Malaysia and Singapore; his election opponent, former General Prabowo Subianto; and 24,000 police and military personnel. The 53-year-old previously served two terms as mayor of Solo and as Jakarta's governor.

"In the name of God, I swear that I will fulfill my obligation as the president of Indonesia as best as I can and as fairly as possible," Widodo said at the swearing-in ceremony on Monday.

Indonesia, an archipelago of more than 17,000 islands, is home to 250 million people, making it the world's fourth-most-populous country, after China, India and the United States. The two terms of President Susilo Bambang Yudhoyono, who left office on Monday, saw democratic consolidation and a focused fight against Islamist militancy. However, economic growth on the back of a commodities boom, has slowed, and weak infrastructure and rampant corruption have hampered the chances for recovery.

'Taking concrete action'

In the evening, Indonesians expect their seventh president - a heavy metal fan who handed over to the state anti-corruption office a bass guitar given to him by Metallica's Robert Trujillo to avoid perceived impropriety - to join rock bands on stage at an outdoor concert. The inauguration caps a remarkable rise for a softly-spoken politician, brought up in a riverside slum. Then the president, nicknamed Jokowi, will get right to work.

In addition to other economic moves, Widodo must soon make a decision on how much to cut subsidies on fuel by. Unless trimmed, they would cost the government over $30 billion (23.5 billion euros) this year, eating up about a fifth of the budget. The move, should Widodo make it, would likely stoke protests from political opponents and could trigger street demonstrations against the president, who won July's election with 53 percent of the vote. Increased petrol prices contributed to the ouster of the autocrat Suharto in 1998.

Some fear that an opposition-dominated parliament - and Widodo's status as a novice in national politics - could make it impossible for him to push through reforms aimed at reviving Southeast Asia's top economy and helping society's poorest. The coalition against Widodo has already captured most of the important positions in the parliament and last month voted to end direct regional elections. For his part, Widodo appears ready for such fights.

"Democracy is about listening to the people and taking concrete action," Joko said in a presidential debate. "That's why I've spent a lot of time visiting villages, markets and fishing communities."

mkg/ksb (Reuters, AFP, dpa, AP)