Accompanied by Indonesia´s Vice President Jusuf Kalla, Guterres examined the damage caused by the September 28 disaster in the city of Palu, reports Efe news.
More than 75 per cent of the 2,073 fatalities, according to the latest official data, occurred in this city where giant tsunami waves caused havoc to areas located hundreds of meters from the coast.
The UN chief also plans to visit Palu's Balaroa neighbourhood, where thousands of homes were swallowed up by land liquefaction, a phenomenon that occurs when a strong shaking, such as that of an earthquake, liquefies soft soil, making the affected terrain sink and release waves of mud.
According to local estimates, some 5,000 people remain missing in Balaroa and the town of Petobo.
On Thursday, the authorities extended the search and rescue mission for survivors for another 24 hours, which will conclude at the end of Friday.
Rescue teams have not found a single survivor under the rubble for more than a week. Indonesian authorities said they will turn the areas most affected by the quake into memorial parks.
The catastrophe on Sulawesi Island is the worst experienced by Indonesia since the tsunami swept the western province of Aceh in 2004, killing 167,000 people.
The Indonesian archipelago is situated within the so-called "Pacific Ring of Fire", an area known for its intense seismic and volcanic activity, which produce about 7,000 earthquakes each year, most of which are of moderate magnitude.
(With inputs from agencies.)