The senior US military commander in Afghanistan has warned that he needs more troops on the ground, or else risk the mission failing.

The confidential report by General Stanley McChrystal, who also commands Nato troops in Afghanistan, was leaked to the Washington Post newspaper.

The White House says that McChrystal has not made a formal request for more soldiers yet, but McChrystal's strategic assessment could fuel US public anxiety over an escalating to the eight-year conflict.

Rob Reynolds reports.