U.N. chiefs in Bosnia pressed ahead Friday with efforts to persuade the warring factions to agree on a four-month cease-fire aimed at paving the way to a political settlement of the 33-month war.

Lt. Gen. Sir Michael Rose, commander of U.N. forces in Bosnia, held nearly three hours of talks in Sarajevo with Bosnian Vice President Ejup Ganic and other members of the Muslim-led government.His immediate superior, Gen. Bertrand de Lapresle, was planning an appeal to rebel Serbs in Croatia to try to bring them into a cease-fire process they have so far ignored.

Rose's discussions in the Bosnian capital were intended to hammer out remaining details of the cease-fire deal under which U.N. troops would police buffer zones between the Bosnian Serb and Bosnian government forces.

U.N. spokesman Alex Ivanko told reporters more talks might be needed to finalize matters.

The proposed four-month cease-fire was the result of a freelance peace mission to Bosnia earlier this month by former U.S. President Jimmy Carter.

Rose and Bosnian Serb military commander Gen. Ratko Mladic said after a meeting Thursday that they still hoped to meet the scheduled Jan. 1 deadline for signing the cease-fire agreement.