Chad's caretaker President Mahamat Idriss Deby has signed a food emergency law.

He said he enacted the law because of the food shortages the country is facing this year and the growing population and humanitarian problems.

The president also sought help before meeting with African Union Commission President Macky Sall and Russian President Vladimir Putin on food imports to Chad.

The United Nations has warned that 5.5 million Chadians - one-third of the country's population - will need humanitarian assistance next year.

The World Food Program (WFP) said in March that more than two million people were at risk of starvation.