Melania Trump’s plane was forced to return to a Washington area military base because of smoke in the cabin.

A spokeswoman for the first lady said “everyone is fine and everyone is safe” after the plane returned to Joint Base Andrews.

Mrs Trump later boarded a different plane to make the visit to a Philadelphia hospital and meet families of children affected by exposure to opioids while in the womb.

According to TV reporters travelling with Mrs Trump, the flight was in the air for about 10 minutes when smoke filled the cabin, and then Secret Service agents rushed to the front of the plane.

It is not clear what caused the problem.

Thomas Jefferson University Hospital has provided care to mothers with opioid use disorder and their newborn children for more than 45 years.

Mrs Trump toured a neonatal intensive care nursery and spoke at a conference on a new system that tracks infants suffering opiate withdrawal.

The visit was part of her Be Best campaign, which focuses on issues affecting children, including the importance of healthy pregnancies.