One of Thailand's largest private companies has promised to donate P10 million for President Rodrigo Duterte's war against illegal drugs, a Cabinet secretary said.

"Charoen Pokphand Group (CP Group) chairman Dhanin Chearavanont said his corporation will donate a modest amount of P10 million for President Duterte's campaign against drugs, and for his rural development program," Agriculture secretary Emmanuel Piñol said in a Facebook post.

The CP Group chief was among Thai business leaders who met with Duterte during the Filipino leader's 2-day official visit to Thailand earlier this week.

Piñol said Duterte assured the Thai magnate, which is that his company "will get the fair return of your investments in my country."

Duterte also assured Chearavanont that corruption will not be tolerated under the present administration and that "nobody will bother" the CP Group's operations.

Chearavanont's group, a conglomerate with interests in food production, distribution, and retail, is involved in pork and chicken production in Luzon.

The CP Group has committed to invest $2 billion to expand its operations to Visayas and Mindanao in the next five years.