Ivan Duque sworn in as the Colombian president in a ceremony held in the Plaza de Bolivar, Bogota on Wednesday.
The Conservative political newcomer, who at 42 is the youngest Colombian President ever, was elected in June after a divisive election campaign where he saw off left-wing rival Gustavo Petro, BBC reported.
After taking his oath, Duque, who succeeds two-term President Juan Manuel Santos, administered the oath of office to his Vice President, Marta Lucia Ramirez, the first woman in Colombia's history to take that office.
In his inaugural address on Tuesday, the former lawyer pledged to tackle corruption and invigorate the economy and said that he wants to overcome the ideological divisions and the social fragmentation existing in the country.
"I want to govern Colombia with unbreakable values and principles, overcoming with popular dialogue, the divisions of the left and the right and the prickly feelings that invite social fracture. I want to govern Colombia with a spirit to build, never to destroy," President Duque said.
He also vowed to change the peace deal with the Revolutionary Armed Forces of Colombia (Farc) rebel group.
His political platform is considered business-friendly after he pledged to cut taxes and boost investment in Colombia's economy.
The new President assumes power at a time of heightened tension with neighbour Venezuela. Earlier this week, Venezuelan President Nicolas Maduro accused the outgoing Colombian President Juan Manuel Santos of an assassination attempt at a military event in Caracas.
The allegation was described as "baseless" by Bogota.