The agency said 1,566 communes nationwide are currently under forest fire warnings, with 411 at Level 3, 327 at Level 4 and 828 at Level 5, the most severe category.
Many of the affected areas have experienced prolonged dry weather and little or no rainfall in recent days.
Amid persistent heatwaves, authorities have urged residents to avoid slash-and-burn farming, while forest protection forces step up patrols and round-the-clock monitoring in high-risk areas.
Authorities also called for the rapid deployment of personnel and equipment to contain any fires and minimise damage.
Vietnam has experienced prolonged periods of hot and dry weather in recent weeks, heightening concerns over wildfire risks across the country.