That Obama expressed 'condolences' in a phone call to Pakistan President Zardari, was a crucial move for US-Pakistan relations, but it doesn't mean business will be back to normal, say analysts.
At least 50 were killed in the suicide attack on the Sunni mosque in Khyber Agency.
Thirty officers were later freed. A Pentagon report is expected to urge a harder line against militants.
The effort, launched on the main supply route to Afghanistan, has suspended supplies sent to US and NATO forces there.