Afghan President Ashraf Ghani has decided to drop his tribal name of Ahmadzai and has asked all government departments and media to use his family name only.

A letter was sent last week by the Presidential Palace's administrative affairs office to all government departments telling them to drop "Ahmadzai" from official documentation, deputy palace spokesman Fayeq Wahidi said. The president had signed the letter, he said.

The Ahmadzai are one of the biggest Pashtun tribes in Afghanistan, based largely in the south and southeast of the country, though Ghani is from Logar province south of Kabul.

Tribal names are sometimes added to the end of a name to denote tribal and geographical affiliation.

Wahidi said Ghani wants to use the name that appears on his national identification card.