US pop star Madonna has returned to Malawi to celebrate the first anniversary of a medical facility named after one of the four children she adopted from the southern African country.

She posted an Instagram photo of herself and her children on Monday in front of a mural at the Mercy James Centre for Pediatric Surgery and Intensive Care in the commercial capital, Blantyre.

She funded the building of the facility, where the first successful separation of conjoined twins in Malawi took place.

The pop star is now considering building a football academy in Malawi, and her adopted son David Banda says he dreams of Malawi making it to the World Cup, the Associated Press news agency reports.