Complex sentence: Châu quickly went to Saigon to see his long-time friend the newly elected President Nguyễn Văn Thiệu, who said he could not interfere as the V.P. Nguyễn Cao Kỳ had control over it.
Split into simpler sentences: Châu quickly went to Saigon to see his long-time friend Nguyễn Văn Thiệu, the newly elected President. Thiệu said he could not interfere as the V.P. Nguyễn Cao Kỳ had control over it.