President Donald Trump plans to speak to the leaders of Thailand and Cambodia as more than half a million people flee a revived border clash, one of eight conflicts the US leader has claimed credit for ending.

Fighting between the neighbors, which has killed at least 12 people, erupted over the weekend along their 800-kilometer (500-mile) frontier. Both sides exchanged artillery fire, and Thailand deployed F-16 jets after accusing Cambodia of firing rockets into civilian areas.