The main purpose of the high-profile visit is to launch a $46 billion investment project: the construction of the so-called China-Pakistan Economic Corridor (CPEC).
This planned network of roads, railways and energy projects is expected to stretch 3,000km, linking Pakistan's deepwater port city of Gwadar on the Arabian Sea with China's far-western Xinjiang region. It would shorten the route for China's energy imports, bypassing the Strait of Malacca between Malaysia and Indonesia, a bottleneck which risks being blockaded during wartime.
China has promised to invest about $34 billion into energy projects and nearly $12 billion into infrastructure.
Deals worth some $28bn are ready to be signed during the visit, with the rest to follow. The sum is expected to significantly outweigh American investment in Pakistan.
A $44 mln optical fiber cable between the two countries is also due to be built.
If the submarine deal is signed, China may also offer Pakistan concessions on building a refueling and mechanical station in Gwadar, a defense analyst said.
China's own submarines could use the station to extend their range in the Indian Ocean.
