China has leaked details of what transpired when North Korean leader Kim Jong Il visited last year, after a North Korean sub sank the South Korean warship Cheonan in March. The Chinese were pretty sure that a North Korean torpedo had sunk the Cheonan, but Kim repeatedly denied it. Chinese leaders kept asking about it, because their diplomats and spies in North Korea reported that the government there was taking credit for sinking the Cheonan, at least unofficially. The official line was that North Korea had nothing to do with it.
To add insult to injury, North Korea asked the Chinese to supply them with 30 Chinese Navy JH-7A bombers, along with the C-801 and C-802 missiles normally carried. China refused, although oil deliveries were increased. The North Koreans had asked for this also, pointing out that their navy was largely stuck in port because of fuel shortages. But the JH-7As are in short supply, even for the Chinese. But what really bothered China was that it would appear that China was supporting North Korean recklessness if these Chinese warplanes showed up in North Korea. Even though Kim made another trip to China a few months after the May visit, to mend fences, the Chinese were still unwilling to supply the missile armed JH-7As, and kept pressing Kim to fix his economy (with the same kind of reforms that had made China rich in the last three decades) and tone down the belligerent behavior.
The JH-7A is a 28 ton, twin engine aircraft, with a 12.9 meter/40 foot wingspan. Even with new engines, it is still underpowered, but it can carry nine ton of bombs, missiles or additional fuel. Now, by using new Chinese made smart bombs and air-to-ground missiles, the JH-7 becomes more useful. The JH-7 is used mainly by the Chinese navy. The aircraft has an operational radius of about 900 kilometers, enabling it to contribute to an attack on Taiwan, or a blockade of the island's ports. North Korea could use it to attack Japan, something the Chinese don't want. The JH7A can carry four C-802 missiles. China plans to build another 150 JH-7s, as an improved version (JH-7A) with the more powerful engines and better electronics, and is apparently doing that now that it has the engines it needs.
The C-802 is similar to the U.S. Harpoon anti-ship missile (which weighs 715 kg/1573 pounds and has a range of 180 kilometers). The Chinese also have the KD-88, which is a land attack version of the C-802 (which is a longer, in size and range, version of the earlier C-801).