The U.S. under President John F. Kennedy intervened in the West New Guinea dispute between Indonesia and the Netherlands, due to Indonesia's purchase of Soviet arms and planned invasion of the territory. U.S. diplomat Ellsworth Bunker brokered the New York Agreement, which eventually ceded West New Guinea to Indonesia in 1969 after a controversial referendum. The administration of Lyndon B. Johnson escalated the war in Vietnam, which greatly heightened tensions with Indonesia in 1964–65. Relations deteriorated further with Indonesia's opposition to the formation of Malaysia that led to war. By mid-1965, Sukarno was edging closer to China, denounced U.S imperialism, and inspired anti-American demonstrations. Following an attempted coup on September 30, 1965, and the ensuing massacres of communists, the pro-Western Suharto came to power in 1968, and the U.S. started providing financial and military aid to Indonesia.