Indonesian President Joko Widodo is cutting short his visit to the United States and will return to Indonesia on Thursday, possibly flying directly to the haze-devastated provinces of South Sumatra or Central Kalimantan.
He made the decision after he received news that conditions in these provinces had deteriorated over the last two days.
"I decided to cancel my trip to the West Coast and may be directly flown into Kalteng or Sumsel," said Mr Joko, referring to the two provinces by their local names, after a telephone conversation with Coordinating Minister for Political, Legal and Security Affairs Luhut Pandjaitan yesterday.
A member of the presidential communications team told The Straits Times that Mr Joko had made the decision after receiving updates on ground conditions.
This was Mr Joko's maiden visit to the US and he was due to meet President Barack Obama yesterday. He was to have travelled to San Francisco tomorrow, where he was to meet officials from Apple, Facebook, Google and Microsoft, as well as fund managers and venture capitalists to pitch Indonesia as "the largest digital economy in South-east Asia".
Those meetings will now be handed over to the other ministers who will remain in the US for the remainder of the trip.
Mr Joko and First Lady Iriana are expected to arrive back home on Thursday morning.
The Indonesian government is preparing for a massive operation, both on land and at sea, for what appears to be an imminent evacuation of thousands of babies and children from their homes in parts of Sumatra and Kalimantan.
Three warships from Indonesia's navy arrived yesterday in the waters off Banjarmasin in South Kalimantan with emergency relief supplies.
The fleet, which includes a naval hospital ship, will also serve as an evacuation point if conditions continue to worsen, particularly in the Central Kalimantan capital of Palangkaraya, where the Pollutant Standards Index has consistently hit four-digit levels.
The Indonesian military has also been given the authority by Mr Joko to take the evacuees out to sea to avoid the haze, if necessary.
The human cost of the crisis, however, is growing.
Indonesia's Health Department has confirmed that 12 people have died of lung infections - among them infants, teenagers and a 65-year-old woman.
The number of people who have been treated for haze-related illness across Indonesia has also breached the half-million mark.
Kompas news, citing official figures, yesterday reported that 503,874 people were suffering from acute respiratory infections, or what the Indonesian health authorities refer to as ISPA.
The bulk of them, or 129,299, were from Jambi province in central Sumatra, from where a Singapore firefighting assistance team had just left last Saturday after a two-week mission.
The city with the second highest number of ISPA patients is Palembang (101,333) in South Sumatra, followed by Banjarbaru (97,430) in South Kalimantan, Pekanbaru (80,263) in Riau - which is just 280km away from Singapore - and Palangkaraya (52,147).
Sumatra and Kalimantan have been the two regions worst hit by the haze from forest and peatland fires since the crisis started three months ago.
This prompted the government last week to prepare for a mass evacuation of infants and children to the warships as well as vessels operated by the Transportation Ministry and state-owned shipping firm PT Pelayaran Nasional Indonesia. These ships form the last resort in the event that cities need to be evacuated after being rendered unliveable owing to high levels of air pollution.