Washington - US President Barack Obama on Friday phoned Ghana's President John Atta Mill to congratulate him on his inauguration and praised the African nation's commitment to democracy.

Atta Mills was sworn in as the president of Ghana in January after winning a tight run-off election.

"President Obama emphasized the importance of Ghana's democratic leadership in Africa, particularly in light of the troubling coups in Mauritania, Guinea, and Madagascar," the White House said in a statement.

It was the second successive peaceful handover of power in a West African nation once prone to coups, and is seen as a vital boost to African democracy after electoral chaos in Kenya and Zimbabwe and coups in Mauritania and Guinea last year.

The presidents also talked about the drug trade that threatens stability in West Africa, the White House said.