Yemeni children have been killed or seriously injured at a minimum rate of five per day in 2017 alone, according to Geert Cappelaere, UNICEF's regional director for the Middle East and North Africa, Xinhua reported.
The outbreaks of cholera and diphtheria have also claimed hundreds of children's lives.
"Much more attention is needed to (be paid to) the situation in Yemen. This has been rightly described as one of the worst humanitarian crises the world has ever known," Cappelaere told reporters.
Yemen, already one of the poorest countries in the Middle East, has been devastated by war since 2015.
"It is fair to say today that every single girl and boy in Yemen is facing acute humanitarian needs," Cappelaere stated, adding that the war and underdevelopment had done "unfortunately nothing good" for the children.
The official stressed there were 200,000 children suffering from severe malnutrition in 2015, already one of the highest numbers in the world by then. Yet, the number has doubled in three years' time till now, according to Cappelaere.
Acknowledging that the cholera outbreak in Yemen had been stemmed and that a vaccination campaign against diphtheria had been conducted in the past two weeks, the official said health and humanitarian workers both in Yemen and from the international community "should pause for a moment to be proud" of these achievements.
"But let's not fool ourselves," Cappelaere added, warning a comeback of the cholera epidemic following the start of the rainy season in a few weeks. He called for "huge and immediate investments" to prevent the possible outbreak.
Further elaborating on the worsening humanitarian situation in the war-torn country, Cappelaere stated that close to 2 million Yemeni children are deprived of education, and that a large proportion of girls are forced to marry at early ages --- 75 percent of them before the age of 18 and half younger than 15.
"Sending your child to beg, sending your child to work, marry(ing) your girl at an early age --- (these) are not choices that any Yemeni father or mother want(s) to make," Cappelaere stressed, underlining that "It is not a choice, it is forced on them because of this brutal war."