ISLAMABAD: Pakistan and Russia on Wednesday signed a landmark defence deal that includes the sale of four Mi-35 ‘Hind E’ attack helicopters to Pakistan.

“The agreement was signed by top defence officials from Pakistan and Russia in Rawalpindi on Wednesday,” said a military source.

Both countries were negotiating the deal for the past year, signalling a major thaw in relations between the two cold-war rivals.

Read: Russia ready to sell four Mi-35 helicopters to Pakistan: report

Chief of Army Staff General Raheel Sharif had also visited Russia in June, after which a draft contract for the delivery of four Mi-35M 'Hind E' combat helicopters was sent to Pakistan from Russia.

General Raheel Sharif had spent about 15 hours at an arms expo near Moscow that featured Russia’s cutting edge weapons and military equipment. He inspected not only the weapon systems on display but also saw their live demonstrations.

Late last year, Russian Defence Minister Sergei Shoigu arrived on a visit to Pakistan which was aimed at discussing bilateral defence cooperation with the Pakistani leadership.

CEO of Russia's Rostec hi-tech corporation, Sergey Chemezov, had also last year said Russia had lifted its embargo on delivery of military hardware and armaments to Pakistan and negotiations were being held on delivering helicopters.

Russia’s Foreign Ministry also said both sides have been negotiating the delivery of helicopters and that Pakistan currently has a number of Mi-17 helicopters delivered by the United States to assist in the fight against militancy.

The Mi-35 helicopter is an exceedingly modernised version of the Mi-24 (Hind) combat helicopter with new onboard equipment and avionics. It also has a more powerful engine and a different tail rotor.

Read more: Russian defence minister arrives in Pakistan to discuss defence cooperation

Pakistan and Russia had signed a bilateral defence cooperation agreement aimed at strengthening military-to-military relations in November last year. The deal had to be followed by another ‘technical cooperation agreement’ to pave the way for sale of defence equipment to Pakistan.

Besides helicopters, Pakistan also appears interested in other Russian hardware.

Russia and Pakistan have lately been working on enhancing defence cooperation and are believed to have already covered a lot of ground. Exchange of visits by military commanders in recent years is an indication of progress achieved in this regard.

India’s decision to enter into tighter embrace with the US had prompted Russia to rethink its defence relationship with Pakistan.