This winter has been "life-threatening" for millions of people in Ukraine, as half the country's energy infrastructure is damaged or destroyed due to the war with Russia, further straining its healthcare system, the regional head of the World Health Organization (WHO) in Europe said on Monday.

The World Health Organization on Monday warned that the upcoming winter would be “life-threatening" for millions of Ukrainians after a series of devastating Russian attacks on the country’s energy grid.

This winter will be about survival," Hans Kluge, regional director for Europe at the United Nations’ health body, told reporters during his visit to Kyiv.

“This winter will be life-threatening for millions of people in Ukraine," he said.

Damage to Ukraine’s energy infrastructure caused by numerous missile strikes “is already having knock-out effects on the health system and on the people’s health," Kluge said.

He said that the WHO has recorded more than 700 attacks on Ukraine’s health facilities since Russia’s invasion began in February.

“Continued attacks on health and energy infrastructure mean hundreds of hospitals and health care facilities are no longer fully operational," Kluge said.

“We expect two-three million more people to leave their homes in search of warmth and safety," he warned.

“They will face unique health challenges, including respiratory infections such as Covid-19, pneumonia, influenza, and the serious risk of diphtheria and measles in under- vaccinated population."

On Monday, Ukrainian President Volodymyr Zelenskyy urged residents in Kyiv to conserve energy, and also implored residents in other hard-hit areas of the country to do the same, including in Vinnytsia, Sumy and Odesa.