In response to the coup against President Ngô Đình Diệm in South Vietnam, Prince Sihanouk cancelled on November 20, 1963 all American aid, and on January 15, 1964 the US MAAG program was suspended when Cambodia adopted a neutrality policy, so the AVRK continued to rely on French military assistance but at the same time turned to Australia, Yugoslavia, the Soviet Union and China for aircraft and training. Already in 1961, Khmer student pilots returning from previous training stints in France had been sent to the USSR for conversion training in Soviet fighter jet types, and in November 1963 the Soviets delivered an initial batch of three MiG-17F fighter jets, one MiG-15UTI jet trainer and one Yakovlev Yak-18 Max light trainer. France continued to deliver aircraft to Cambodia in 1964-65, supplying sixteen night attack Douglas AD-4N Skyraiders and six Dassault MD 315R Flamant light transports, soon followed by more Alouette II and Sud Aviation SA-316B Alouette III light helicopters and ten Gardan GY-80 Horizon light trainers, which replaced the obsolete MS 733 Alcyons. The Yugoslavians provided at the time four UTVA-60AT1 utility transports, whilst the USSR delivered one Ilyushin Il-14 and eight Antonov An-2 Colt transports, and China sent one Chinese-built FT-5 jet trainer, ten Shenyang J-5 fighter jets, and three &lt;a href="Nanchang%20CJ-6"&gt;Nanchang BT-6/PT-6&lt;/a&gt; light trainers. Not to be outdone, the Soviets delivered in April 1967 a second batch of five MiG-17F jets and two Mil Mi-4 Hound light helicopters.