The center said on Tuesday that drought and saltwater intrusion from the sea in the region in the next few months could be as devastating as in 2016, the delta's worst drought since data was first available in 1926.

It had caused losses worth VND8.9 trillion ($400 million). The prolonged drought, caused by El Nino, saw more than 400,000 families suffer from lack of water and destroyed 250,000 hectares of rice, 130,000 hectares of cash crops and 30,000 hectares of fruits.

The center's data shows that between June and October this year rainfall in the upper Mekong region was 35-40 percent less than normal. As a result the water level in the upper part of the Mekong is now about 0.4-0.7 meters lower than normal.

To cope with the situation, the Ministry of Agriculture and Rural Development has instructed the delta provinces to plant the winter-spring rice crop earlier than usual and ensure people store water at home, Nguyen Truong Son, deputy general director of the General Department for Disaster Prevention, said.

Provinces on the verge of being hit by the drought like Ben Tre, Tien Giang and Tra Vinh planted rice on more than 400,000 hectares -- 150,000 ha more than the previous year – as early as at the beginning of October. They usually do it only in November.

Son also said the ministry has instructed agencies overseeing irrigation construction works to speed them up to reduce the damage caused by drought and saltwater.

Local authorities plan to assist farmers in taking up new livelihoods so that they are affected less by climate-related disasters.

Saltwater intrusion occurred in the delta at least four months earlier than usual this year and has been severe. According to the Southern Institute of Irrigation Science, the saltwater could infiltrate 10-15 kilometers further inland than usual, affecting the lives of some 50,000 families.

The delta has struggled with the late arrival of the annual flooding and receding water levels in recent years.

The floods not only replenish its supply of fish and other aquatic species but also bring large volumes of fertile alluvium that have nourished it for centuries.

The Mekong River Commission had said in November that countries in the lower Mekong basin might suffer from severe to extreme drought from now until January 2020, with Thailand and Cambodia being hit harder than Vietnam and Laos.