Ten aircraft, including from Malaysia and Singapore, doused parts of South Sumatra, Indonesia, to fight forest fires as leaders met to discuss ways of fighting the haze spreading around the region.

A CL415 Bombardier from Malaysia that can scoop and drop 6 tons of water and a Chinook helicopter from Singapore, which pours water from a hanging tank, would be joined by a Lockheed L100 Hercules Air Tanker with a 15-ton capacity, the South China Morning Post reported, citing Indonesia's disaster mitigation agency. Officials are adding to the 25,000 personnel and aircraft that Indonesia has deployed to little effect.

“Malaysia is prepared to increase our assistance in dousing the fires," the Post reported Malaysian Prime Minister Najib Razak as saying, after a meeting with Indonesian President Joko Widodo in Jakarta. “We consider the haze a serious issue as it’s a burden to Malaysians and Indonesians,” Najib said.

The haze is caused by Indonesians burning forests to make way for palm oil and paper plantations. It's carried by winds to neighboring countries, where it has forced school shutdowns and the cancelation of sporting events in Indonesia, Malaysia and Singapore, and hurting tourism in places like Phuket.

Pressure -- and even anger around the region -- forced Widodo to do an about-face last week and request help from Singapore, Malaysia, South Korea, China, Australia and Russia, to address the issue.

On Saturday, Widodo canceled a visit to Jambi in South Sumatra because visibility dropped to 600 meters, less than the 1 kilometer required for landing, the Straits Times reported.

Widodo and Najib, whose countries produce 85 percent of the world's palm oil, agreed to start working on global standards for the palm oil industry aimed in part at addressing the burning of forests, the Straits Times reported.