The head of the UN Children's Agency, UNICEF, said as the world struggles to respond to the Covid-19 pandemic, a child survival crisis looms in the months ahead.
Henrietta Fore said already fragile health systems were growing weaker with lockdowns disrupting critical health services including vaccinations.
Ms Fore said with a global recession fast approaching, many children could fall below the poverty line.
"Unless we act now, the Covid-19 pandemic will turn into a child survival crisis. I urge all governments to put children first in their commitments and responses."
Ms Fore also said governments needed to ensure that while they were addressing one crisis, it did not come at the expense of another.
Pacific children at risk
Last month, UNICEF warned that thousands of children living in the Pacific were at risk in the aftermath of Cyclone Harold.
The storm tore through Solomon Islands, Vanuatu, Fiji and Tonga, causing widespread destruction to buildings and damage to food crops and contaminating water supplies.
More than 30 people died and dozens were injured while thousands were forced to flee their homes.
UNICEF's Pacific representative, Sheldon Yett, said the agency supported government responses in Vanuatu, Fiji and the Solomons who were also faced with the challenges of the Covid-19 pandemic.
'The greatest weapons we have'
Meanwhile, the head of the UN Children's Agency said this week that food insecurity was on the rise with water, sanitation and hygiene services strained leaving children at risk of disease and malnutrition.
In some communities, Henrietta Fore said, expecting mothers were unable or afraid to go to the health centres to give birth.
"In others, health workers have no access to water, soap and other critical supplies to safely treat patients," she said.
Ms Fore urged governments to invest in critical health, nutrition and WASH services to protect children from disease and reduce preventable deaths.
She said there was a need to increase access to medicine and nutritious food, and to clean water and soap for handwashing.
"We must ensure that every mother can safely deliver her baby during the pandemic supported by a trained and equipped health worker."
She said children needed to be reached for their routine vaccinations.
"These are the greatest weapons we have to prevent future outbreaks and epidemics," the UNICEF head said.