KUALA LUMPUR, Oct 5 (Reuters) - Malaysia called on neighbour Indonesia and a grouping of Southeast Asian nations to take action as air quality worsens across the country due to fires in Indonesia, its environment minister told Reuters on Thursday.

Air quality has hit unhealthy levels in several parts of Malaysia in recent days, with Kuala Lumpur blaming fires in Indonesia -- though Jakarta has denied detecting any smoke drifting over its borders into Malaysia.

Almost every dry season, smoke from fires to clear land for palm oil and pulp and paper plantations in Indonesia blankets much of the region, bringing risks to public health and worrying tourist operators and airlines. Many of the companies that own these plantations are foreign or foreign-listed.

Fires that sent haze billowing across the region in 2015 and 2019 burned millions of hectares of land and produced record-breaking emissions, according to scientists.

Nik Nazmi Nik Ahmad, Malaysia's minister of natural resources, environment and climate change, said he has sent a letter to his Indonesian counterpart this week on the haze.

"We submitted our letter to inform the Indonesian government and urging them to hopefully take action on the matter," he said in an interview. "We cannot keep going back to having haze as something normal."

He reiterated that most of the hotspots indicating fires were in Indonesia.

The government has also sent letters to Malaysian-owned plantation companies that operate in Indonesia to ensure they comply with laws and prevent burning, he said.

He called for joint action by the Association of Southeast Asian Nations (ASEAN) either through legislation or agreement to prevent the yearly haze.

"I hope that every country will be able to be open in order to find a solution because the damage to the economy, to tourism, but especially to health, is immense from the haze," he said.

He said Malaysia was still "seriously" considering a law similar to Singapore that holds companies liable for air pollution.

But there were concerns over whether Malaysia would be able to prosecute polluters based overseas, he said.