The U.S. opposed an expansion of Vietnamese influence in Indochina, and in the mid-1980s supported insurgents opposed to the regime of Heng Samrin, approving $5 million in aid to the KPNLF of former prime minister Son Sann and the pro-Sihanouk ANS in 1985. Despite this, Pol Pot's Khmer Rouge remained the best-trained and most capable of the three insurgent groups, who despite sharply divergent ideologies had formed the Coalition Government of Democratic Kampuchea (CGDK) alliance three years earlier. China continued to funnel extensive military aid to the Khmer Rouge, and critics of U.S. foreign policy claimed that the U.S. was indirectly sponsoring the Khmer Rouge due to its diplomatic recognition of the CGDK.