The question of whether or not to send more troops to Afghanistan has been the subject of much debate in the United States in recent weeks.

Barack Obama, the US president, is said to be exploring alternatives.

Earlier this week, the US military commander General Stanley McChrystal's grim assessment of the realties on the ground in Afghanistan was leaked to the press.

His formal request for additional troops may not be met because of uncertainty within the Obama administration over whether to escalate the US commitment to the eight-year-long war.

There is a suggestion that Obama is considering a plan favoured by Joe Biden, the US vice-president, that calls for the US to potentially scale back its troop numbers in Afghanistan and focus more attention on Pakistan.

Al Jazeera's John Terrett reports from Washington DC.