from original plans. In 2011, the Ministry of Defence had planned on buying the first 10 aircraft for evaluation after 2012 and 60 production standard aircraft after 2015. These plans were refined under the State Armament Programme from 2011 to 2020 (GPV-2020), with serial production hoped to begin in 2016; the Ministry of Defence was planning to acquire 52 aircraft by 2020, and another 150–160 by 2025. Additionally, export orders for 250–300 FGFA were expected to begin in 2017. Plans were greatly cut down in 2015 as a result of technical obstacles encountered during testing, India's unclear commitment to the partnership, and Russia's economic downturn due to Western sanctions after its annexation of Crimea and the drop in oil prices. Russian Deputy Minister of Defence Yury Borisov stated in 2015 that the Russian Air Force would slow production, reduce its initial order to 12 fighters, and operate large fleets of upgraded fourth-generation fighters such as the Su-35S and the Su-30SM. In 2017, Borisov stated that the PAK FA would most likely enter service in 2018 and be part of the new State Armament Programme from 2018 to 2027 (GPV-2027). On 30 June 2018, an order for 12 aircraft was agreed, while deliveries to the Russian Armed Forces was pushed back again to 2019 with the first aircraft planned to join fighter regiments at the Lipetsk Air Center. At the same time, Borisov praised the Su-35S, stating that it was comparable to the Su-57 except for the stealth features while being more affordable. Due to the substantially higher cost of the Su-57 compared to the Su-35S and Su-30SM, the design was placed on hold for mass production until the need arises. On 22 August 2018, during the International Military-Technical Forum «ARMY-2018», the Defence Ministry and Sukhoi signed the first contract for delivery of two serial Su-57 fighters scheduled for 2019 and 2020 respectively. In January 2019, the Ministry of Defence announced they hoped to conclude a second contract for 13 more aircraft in 2020. However, on 15 May 2019, the acquisition plan drastically changed when Russian President Vladimir Putin announced that 76 aircraft would be purchased and delivered to the Aerospace Forces by 2028. This came after the negotiations were able to lower the price of the Su-57 and equipment by 20%. The contract for the 76 aircraft was formally signed on 27 June 2019 at the International Military-Technical Forum «ARMY-2019».