The Khmer Rouge wanted to establish Cambodia as a self-sufficient state. They did not reject foreign assistance altogether although regarded it as pernicious. While China supplied them with substantial food aid, this was not publicly acknowledged. Shortly after the taking of Phnom Penh, Ieng Sary travelled to Beijing, negotiating the provision of 13,300 tons of Chinese weaponry to Cambodia. At the National Congress meeting in April, the Khmer Rouge declared that it would not permit any foreign military bases on Cambodian soil, a threat to Vietnam, which still had 20,000 troops in Cambodia. To quell tensions arising from recent territorial clashes with Vietnamese soldiers over the disputed Wai Island, Pol Pot, Nuon Chea, and Ieng Sary travelled secretly to Hanoi in May, where they proposed a Friendship Treaty between the two countries. In the short term, this successfully eased tensions. After Hanoi, Pol Pot proceeded to Beijing, again in secret. There he met with Mao and then Deng. Although communication with Mao was hindered by the reliance on translators, Mao warned the younger Cambodian against uncritically imitating the path to socialism pursued by China or any other country, and advised him to avoid repeating the drastic measures that the Khmer Rouge had imposed before. In China, Pol Pot also received medical treatment for his malaria and gastric ailments. Pol Pot then travelled to North Korea, meeting with Kim Il Sung. In mid-July he returned to Cambodia, and spent August touring the South-Western and Eastern Zones.