The pledge comes as smoke from Indonesian wildfires blankets parts of Southeast Asia, closing schools and fuelling a surge in respiratory complaints across the region.
The city-state topped IQAir's live ranking of the world's most polluted major cities again early Friday, with Jakarta second and Kuala Lumpur fifth.
"We are looking into which companies may be responsible for the fires," Wong said in a Facebook post late Thursday.
"Where warranted…
Singapore has reported worsening air quality due to haze from Indonesian forest fires. The central region has a PSI of 226, considered very poor. Meanwhile, Prime Minister Lawrence Wong is considering legal action against companies involved.