A mother accidentally smothered her four-week-old daughter to death after falling asleep while breastfeeding on a flight between the US and Kuwait, an airline says.

The 29-year-old woman was taking her baby from Washington to meet extended family in Kuwait when the tragedy occurred on November 24, London's Daily Mail reports.

The woman appears to have fallen asleep while breastfeeding her daughter and woke to find her not breathing.

Crew members on the United Airlines flight were alerted to the situation by the woman's screams.

The plane was diverted to London while a doctor on board the plane tried without success to revive the little girl.