China has signed an arms deal with Pakistan which experts say is worth between $4-5 billion. The arms deal, believed to be China's biggest, will deliver a total of eight new submarines to Pakistan.
China's Global Times newspaper says with the deal, China has overtaken Germany to become the world's third-largest arms exporter.
Pakistan's minister for defence production Tanveer Hussain has confirmed the deal while opening a new exhibition center at Pakistan's Defence Export Promotion Organization.
He says four of the submarines will be built in China, while the other four will be constructed in Pakistan under a technology transfer agreement. Pakistan will also build a submarine training center in its main port city, Karachi.
Hussain would not reveal the model of the new submarines, though analysts believe they will be a variant of the S-20, which is the export version of China's Type 039A/Type 041 class diesel-electric submarine.
The new deal will modernize Pakistan's submarine fleet, currently made up of eight subs, which include two French Agosta-class 70-B subs and three Agosta-class 90-B subs.
Experts say China has been transferring weapons technology to Pakistan for some time.
Not much information is being released about the capabilities of the Chinese submarines which are part of the deal with Pakistan. Research analyst in the Defence and Military Analysis Programme at the International Institute for Strategic Studies, Tom Waldwyn says as it "benefits countries on both sides to keep this a secret".
He says if the subs are AIP S-20s, they would give Pakistan "greater operational flexibility through increased endurance."
Military analyst Brian Cloughley, another military analyst who has been closely watching the arms partnership between the two countries says even with the transfer of technology, Pakistan will remain reliant on China for arms.
"It is in the interests of both parties to have as much as possible manufactured in Pakistan, but of course the really high-tech systems will have to come from China, as it's simply not cost-effective for Pakistan to gear up to make them," he says.