Balkan Leaders Near Peace Pact, Officials Say : Diplomacy: Christopher cuts short Japan trip to return for final stage. U.S. braces for fight over troop deployment.

Leaders warring over Bosnia have virtually wrapped up a peace agreement to end almost four years of bloody conflict, prompting Secretary of State Warren Christopher to cut short a trip to Japan so that he may participate in final negotiations this weekend, U.S. officials said Wednesday.

A senior Administration official said it may take a day or two of talks after Christopher’s return to complete the treaty. But there is little doubt that agreement will be reached among the Balkan presidents who have been negotiating since Nov. 1 at Wright-Patterson Air Force Base in Dayton, Ohio, the official said.

The official provided no details of the agreement, which is expected to divide Bosnia-Herzegovina about equally between rebel Serbs and the newly reorganized Muslim-Croat federation.

The Muslim-led central government will retain authority over foreign policy and such international matters as trade and air-traffic control.

Christopher arrived in Osaka, Japan, early today after an overnight flight from Dayton following more than 12 hours of talks Tuesday with Bosnian President Alija Izetbegovic, Serbian President Slobodan Milosevic and Croatian President Franjo Tudjman.

Just after Christopher departed, State Department spokesman Nicholas Burns said the rival factions had narrowed their differences during Tuesday’s marathon negotiations.

Christopher went to Osaka for the annual Asia-Pacific economic forum but was prepared to return to Dayton on short notice if the Bosnia talks progressed to the point where his participation was considered important, Burns said.

Although Assistant Secretary of State Richard Holbrooke heads Washington’s delegation at Dayton, officials said earlier that no agreement will be signed without Christopher present.

The expectation of an imminent peace accord came as President Clinton and the Republican-controlled Congress braced for a partisan legislative battle over Administration plans to send 20,000 U.S. troops to the Balkans to help enforce an agreement.

The House is expected to vote Friday or Saturday on a measure by Rep. Joel Hefley (R-Colo.) that would bar the Clinton Administration from sending troops to Bosnia without the approval of Congress, a vote that both Republicans and Democrats see as a key test of congressional sentiment on the issue.

If approved, the legislation could torpedo a Bosnian agreement because all three of the competing parties have made it clear that they will not sign a pact without the promise of U.S. troops.

Republicans aimed a continuing stream of criticism at Clinton’s Bosnia policy.

House Speaker Newt Gingrich (R-Ga.) told reporters that the President’s nine-page defense of his troop plans, issued Tuesday, “did not improve by one vote his position. . . . Bosnia policy is quicksand.”

Nevertheless, the Administration proceeded on the assumption that Congress will eventually allow the troops to be sent.

A senior official said U.S. and European mediators and the warring factions have already agreed on a schedule for putting a peace plan into operation.

About two weeks after the agreement is approved in Dayton, a Balkan economic conference will meet in London to line up international donors to support reconstruction of the war-torn country.

Clinton has said the United States will contribute about $600 million over several years to the effort, which will require substantial contributions from other affluent nations.

After the London meeting, the factions will meet in Paris for a signing ceremony.

At the same time, the North Atlantic Treaty Organization will put the finishing touches on plans to send about 60,000 troops, including the 20,000 Americans, to Bosnia to separate ethnic armies and enforce the peace treaty.

Meanwhile, the State Department rebuked Croatia’s Tudjman for promoting a Croatian militia member who just days before had been indicted for war crimes by the special international tribunal on war crimes in The Hague.

“This decision is completely contrary to the obligations and commitments that the Croatian government has to the international community and to the United Nations to cooperate in the search for those people who are under suspicion of having committed atrocities during the past four years,” Burns said.

Times staff writer Art Pine contributed to this report.