"Myanmar has the third-highest malnutrition rate across South-East Asia after Cambodia and East Timor," said Bertrand Bainvel, United Nations Children's Fund (Unicef) representative in Yangon.
Myanmar's official entry into the Scaling Up Nutrition movement, launched by the UN in 2010, brought ministries and UN agencies together in Naypyitaw, the capital, for a three-day meeting.
The programme aims to help governments, civil society groups, donors, businesses and researchers coordinate to improve nutrition, and supports specific approaches such as breast-feeding in early life and treatment of severe malnutrition.
"This is an important step towards ending child malnutrition and better increasing the chances of all Myanmar children reaching their fifth birthdays," Bainvel said at the launch.
Malnutrition in Myanmar accounts for 4% to 6% of all under-five deaths in the country, according to UN estimates.
"If all nutrition interventions combined achieved 99% coverage, stunting could be dramatically reduced and the lives of some 10,000 Myanmar children could be saved annually," said Krongthong Thimasarn, World Health Organisation (WHO) representative in Yangon.
Myanmar, which was under the rule of a military junta between 1988 and 2010, was ranked among the lowest recipients of development aid in the past two decades because of its pariah status among Western democracies.
Economic sanctions against the country were largely dropped in 2012 after elected President Thein Sein came to power in March 2011, and swiftly introduced a series of political and economic reforms that endeared his government to the West.