Young Syrians are having their childhoods "smashed to pieces" by the conflict, British Prime Minister David Cameron's wife said on Wednesday following a visit to a refugee camp in Lebanon.
Samantha Cameron visited Bekaa Valley, close to the Syrian border, on Tuesday on a trip with London-based charity Save the Children.
"With every day that passes, more children and parents are being killed, more innocent childhoods are being smashed to pieces," the 41-year-old said in a statement issued by the charity.
She added: "As a mother, it is horrifying to hear the harrowing stories from the children I met today. No child should ever experience what they have."
The UN says more than 1.1 million Syrians have fled -- mostly to Jordan, Iraq, Lebanon and Turkey -- and some four million others have been displaced inside their war-torn country.
Lebanon has taken in some 360,000 refugees from the brutal conflict across the border, according to the UN's refugee agency.
Cameron spoke to children who had witnessed the violent deaths of their parents and siblings, as well as mothers whose children were killed by snipers, Save the Children said.
The mother-of-three was the creative director of upmarket British stationers Smythson until 2010, when her husband was elected and she switched to a part time consultancy role at the company.
The Camerons' eldest son Ivan, who had cerebral palsy and epilepsy, died aged six in 2009.