Indonesia’s aerial firefighting efforts have been hampered for more than a week by poor visibility from the forest-fire haze, as the smoke continues to spread across Southeast Asia.

Dense smog has prevented water-bombing and cloud-seeding operations in Central Kalimantan on Borneo, forcing authorities to rely on ground crews, the country’s disaster management agency said during a cabinet meeting convened Monday by President Prabowo Subianto. Prabowo said rainfall may be the only way to clear the smog and allow aerial operations to resume.

“In the end, it really comes down to rain,” Prabowo said while referring to the haze in a video of the meeting posted on YouTube. He praised ongoing operations and called for more comprehensive fire prevention measures at the village level. Authorities expect rains from mid-October to help contain the fires.

Indonesia is battling its worst fire season in years. Prolonged dryness, exacerbated by a powerful El Niño, has created conditions for land-clearing fires to burn out of control and emit noxious fumes, fueling health and diplomatic concerns across the region.

Singapore, Jakarta and Kuala Lumpur were among the world’s 10 most polluted major cities on Tuesday morning, according to live rankings from Swiss air-quality monitoring company IQAir.

The worsening haze has prompted Malaysia to seek more effective regional mechanisms to tackle transboundary pollution. Foreign Minister Mohamad Hasan said he would raise the issue at a meeting of Southeast Asian foreign ministers in Manila next month.

Singapore has also offered assistance. Sustainability and Environment Minister Grace Fu said Saturday that the city-state was in contact with Indonesian authorities and stood ready to help contain the fires, according to the Straits Times.

Indonesia has ruled out declaring a national disaster over the fires and haze, with Coordinating Minister for Political and Security Affairs Dudung Abdurachman saying the government is capable of handling the crisis. The country could still tap emergency funds and accept international aid and equipment with government approval, though Dudung said offers of foreign assistance were not discussed during Monday’s meeting.

Authorities are prioritizing six provinces on the islands of Sumatra and Borneo, the disaster management agency said, with firefighting continuing across 640 hectares (1,580 acres). That includes more than 500 hectares in the Tanjung Puting National Park area in Central Kalimantan, a popular destination for foreign tourists that is home to endangered orangutans, and where visibility had fallen to as little as 500 meters, according to a local official.

Prabowo pledged 200 portable water pumps and 2 billion rupiah ($118,000) to fund drilling at 200 locations to support firefighting operations around Tanjung Puting.

The ASEAN Specialised Meteorological Centre said showers forecast for Peninsular Malaysia and parts of Sumatra and Borneo could ease the haze in some areas, though persistent dry weather elsewhere continues to pose a risk of transboundary pollution.