The Japanese government will provide the aid through the United Nations Children's Emergency Fund.
The direct assistance will help Vietnam combat the worst drought and salinity in almost a century, which have cost the Southeast Asian country about VND6.4 trillion ($287 million) in the first four months of this year, according to Vietnam's General Statistics Office.
The package will be mainly used to provide clean water and food aid in affected areas.
According to a joint assessment undertaken by the Vietnamese government, the United Nations and non-governmental organizations in March, the drought and saline intrusion, which have mainly hit Vietnam's south central region, Central Highlands and southern Mekong Delta, have left as many as 2 million people without access to clean water and 1.1 million in need of food aid.
More than 60,000 women and children are already malnourished.
Vietnam has appealed to the international community for $48.5 million in emergency aid to address the worsening drought.