Asif said that General Sharif had been "given permission to head the military alliance after completion of all legal formalities and requirements" by the Pakistan government three days ago.
Asif said the former chief was given the No Objection Certificate after approval from the Pakistan Army's General Headquarters (GHQ) in Rawalpindi.
Gen (retd) Raheel Sharif today left for Riyadh in a special Saudi plane, which had arrived to pick him up earlier today.
Prime Minister Nawaz Sharif has said that Pakistan and Saudi Arabia have always stood by each other in testing times and the people of Pakistan have deep emotional attachment with the Kingdom being the custodian of the Two Holy Mosques.
Opposition parties have been criticising the government over the controversial appointment, claiming that the alliance is formed against Shia-majority Iran and will harm Pakistan's relations with its neighbour.More news: US Treasury says China does not manipulate its currency
The news also seemed to go against what the defence minister himself had assured Parliament of on April 13, the report said.
"Prime Minister Nawaz Sharif and former COAS Gen Raheel Sharif will attend the event", he had said.
A statement carried by Saudi state news agency SPA in December 2015 said the new coalition would have 34 members, though more have joined since then.
Earlier this week, Iran's ambassador to Pakistan Mehdi Honardoost expressed reservations over Sharif's role as head of the Saudi-led military alliance.