Pakistani Prime Minister Nawaz Sharif left for Saudi Arabia on Friday to attend the funeral of King Abdullah bin Abdul Aziz, state TV reported.

King Abdullah passed away in Riyadh early in the morning on Friday at the age of 90.

Pakistan also announced one-day official mourning for the late Saudi King, who was widely believed a friend of Pakistan.

Earlier the Pakistani prime minister expressed deep sorrow and grief over the death of Saudi King Abdullah.

"Being Custodian of the Two Holy Mosques, King Abdullah had a deep respect in the hearts of Pakistani people," Nawaz Sharif said in a statement.

He said Pakistan stands with King's family and Saudi nation in this hour of grief.

The prime minister visited Saudi Arabia last week to inquire the health of King Abdullah.

President Mamnoon Hussain also expressed deep grief and sorrow over the demise of Saudi King Abdullah Bin Abdul Aziz.

In his condolence message, he said the death of Abdullah Bin Abdul Aziz is an irreparable loss to the Muslim world.

In his condolence message, Punjab Chief Minister Shahbaz Sharif said the death of Abdullah Bin Abdul Aziz has deprived Pakistan of a true friend.

"We stand by the Saudi people in this hour of grief," he said in a statement.