An Indonesian court has sentenced a New Zealand woman to 2 ½ years in jail for possessing methamphetamine.

The Denpasar District Court made the ruling against Myra Lynne Williams on Thursday. The 28-year-old was arrested last August last year when customs and narcotics agency officers confiscated 0.43 grams of crystal methamphetamine upon her arrival at Bali's airport from Melbourne.

Indonesia has very strict drug laws and convicted traffickers are often executed by firing squad. More than 150 people are on death row, mostly for drug crimes and about a third of them are foreigners.

Eighteen people convicted of drug-related offenses have been executed under the current administration of President Joko "Jokowi" Widodo.