Cambodia's government-in-exile in Peking issued a peace plan calling for a partnership with Cambodia's Hanoi-backed Heng Samrin regime. It also urged the phased withdrawal of Vietnamese troops under a U.N.-supervised truce. Diplomats said it was the first time that Prince Norodom Sihanouk and his two coalition partners have formally proposed forming a government with Heng Samrin. Vietnamese Embassy officials in Peking said they have not seen the peace plan. However, Vietnam previously said it would not deal with Sihanouk's coalition as long as the Communist Khmer Rouge remains a member.