The envoy, Miroslav Lajcak, has already met with opposition leaders who want the union between Serbia and Montenegro to survive, RFE/RL's South Slavic Service reports.
He also plans to meet with Prime Minister Milo Djukanovic and other pro-independence officials who intend to hold a referendum by the end of April.
Under discussion are the conditions under which a vote might be held and regulations governing campaigning, media coverage. and security measures.
The European Union brokered a deal in 2003 that formed the loose union, but relations between Serbia and Montenegro remain strained.