A briefing by the head of the U.S. Central Command to Pakistani officials on a November 26 cross-border NATO air attack that killed 24 Pakistani soldiers and severely strained ties with Washington has been cancelled, a Pakistani official said on Friday.

News that General James N. Mattis' visit to Pakistan has been cancelled came a day after the United States announced that its investigation into the attack found both American and Pakistani forces were to blame for the border incident.

(Reporting by Qasim Nauman; Writing by Michael Georgy; Editing by Paul Tait)