WASHINGTON: US President Barack Obama telephoned Prime Minister Nawaz Sharif on Wednesday and expressed his condolences over the death of 141 people — including 132 children — killed in the attack on Peshawar's Army Public School.

Obama called Sharif and conveyed his deepest condolences and sympathies from the people of United States on the brutal massacre.

"We stand by the people of Pakistan in this hour of grief," Obama said, adding that the US "would do anything to support Pakistan in its war against terrorists".

The 141 were killed when insurgents stormed the army-run school in Peshawar on Tuesday and systematically went from room to room, shooting children during an eight-hour killing spree.

The attack was claimed by the Tehreek-i-Taliban Pakistan (TTP) as revenge for a major military offensive in the Federally Administered Tribal Regions (Fata).