Chinese state media reported March 25 that China has concluded a large-scale weapons purchase agreement with Russia . Beijing has long been thought to be interested in the advanced Russian submarines and fighter aircraft included in the weapons package, and the media report is the strongest confirmation yet that a deal has been struck. According to the report, the contract included the purchase of 24 Su-35 multirole fighter jets, four Lada-class diesel-electric submarines and continued cooperation in developing S-400 long-range surface-to-air missiles, 117S turbofan engines, Il-476 large transport aircraft and Il-78 aerial refueling tankers . Russia has a long history of exporting weapons to China. In the decade following the collapse of the Soviet Union, arms sales to India and China essentially allowed Russia to maintain its defense industry and pursue research and development at a time when funds for the Russian military had dried up.