An Indonesian province that suffers annual outbreaks of haze-belching fires said Tuesday it was declaring an early alert to prevent blazes burning out of control after forecasters predicted a dry 2017.

Riau, on the western island of Sumatra, announced the move after a few "hotspots" -- areas of extreme heat detected by satellites which often indicate fires -- were sighted this month.

It came a day after President Joko Widodo urged local authorities to take early steps to prevent a repeat of the haze crisis of 2015.

The fires occur every year on Sumatra and the Indonesian part of Borneo island, typically during the months-long dry season later in the year.

The fires are deliberately started to clear land quickly and cheaply for palm oil and pulpwood plantations.

The 2015 blazes were among the worst on record and sent clouds of toxic smog floating across Southeast Asia, leading large numbers to fall ill.

A US academic study estimated that the crisis may have led to over 100,000 premature deaths.

The alert status in Riau -- below the more significant "state of emergency", which typically indicates a large number of fires burning fiercely -- was set to remain in place until April and allows the province to request more resources from central government.

"We are preparing helicopters for water-bombing to help the regional government," disaster agency spokesman Sutopo Purwo Nugroho told AFP. Several provinces were criticised in 2015 for failing to declare emergencies quickly enough.

The blazes typically start earlier in Riau due its high concentration of carbon-rich peatland and a widespread practice of using fire to clear land.

The Meteorology, Geophysics and Climatology Agency has predicted that this year will be drier than 2016, when an unusually long rainy season prevented major outbreaks of fires.

Widodo urged efforts to stop the blazes including setting up fire prevention task forces. He told a meeting of ministers and senior officials: "It is only January but it is already looking dry, therefore we cannot be careless."