Indonesia President Joko Widodo is cutting short his visit to the United States and will return to Indonesia, possibly flying directly to South Sumatra or Central Kalimantan.

He made the decision after he received news that conditions in the two regions affected by the haze, have worsened over the last two days.

"I decided to cancel my trip to the West Coast and I may fly directly to Kalteng (Central Kalimantan) or Sumsel (South Sumatra)," said Mr Joko, after a telephone conversation on the haze situation with Coordinating Minister for Political, Legal and Security Luhut Pandjaitan on Monday.

A member of the presidential communications team told The Straits Times that Mr Joko had made the decision after receiving updates on ground conditions.

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.

This comes as the forest fires, which produce the toxic haze, continue to burn unabated despite the extensive firefighting resources dedicated to putting them out.

Three navy warships have arrived in Kalimantan with relief supplies, with more put on high alert to deploy to affected areas soon.

In total, 27 ships, including 16 civilian vessels, are involved in the rescue operation.

This was Mr Joko's maiden visit to the US, and he was due to travel to San Francisco on Wednesday, where he would meet, among others, representatives 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 relevant ministers, who will remain in the US for the remainder of the trip.

Mr Joko, however, will still meet with his American counterpart, President Barack Obama before he leaves Washington DC.

The president and First Lady Iriana are expected to arrive in Indonesia on Thursday.