Media outlets cited unnamed government sources as reporting that the Pakistani general had flown to the Saudi capital, Riyadh, on Friday.
The former Pakistani chief of Army staff, who retired late last year, reportedly plans to build the military bloc from scratch and recruit forces for it.
The objectives or Terms of Reference (ToR), of the army has not been clarified as of yet and still remains shrouded in secrecy.
The Saudis financing the alliance, which is to be formed by recruits from 40 Muslim-majority countries, claim the force is to fight extremist outfits such as the Daesh Takfiri terrorist group.
This as Saudi Arabia is also currently heading a military bloc that has been engaged in a deadly aggression against the impoverished country of Yemen. Some 12,000 Yemenis have reportedly been killed in the Saudi-led attacks with Riyadh failing to achieve its declared goals.
To get the post, Sharif was obliged to obtain a special permit named "no-objection certificate," endorsed by Pakistani authorities.
Many people from all walks of life, including politicians, retired army officers and intellectuals, Shia and moderate Sunni Muslim leaders and lawmakers, see Sharif's controversial appointment as a violation of a parliamentary resolution passed in April 2015 that called for Pakistan to maintain a policy of neutrality, particularly in the Saudi-led military aggression against Yemen, which is aimed at restoring power to a pro-Riyadh government there.
Critics are asking why the Pakistani authorities signed the no-objection certificate for Sharif without first stamping out the details, aims and objectives of the alliance.
A recent editorial published in Dawn daily has questioned the secrecy surrounding the matter.
“The secrecy surrounding the move raises many questions about our policy-making process. The argument that the government could not refuse the Saudi request makes us appear more like a client state,” the paper said.