The United States is appealing to all sides in the conflict in the Democratic Republic of Congo to honor a ceasefire agreement signed three years ago in Zambia's capital Lusaka and refrain from further military action.

State Department spokesman Richard Boucher Monday called on all factions to halt fighting around the southeastern Congolese town of Moliro. On Saturday, the rebel Congolese Rally for Democracy-Goma Faction captured Moliro from Congolese army forces. In response, according to the rebel group, two government gunboats shelled Moliro Sunday overnight. The group said there were no casualties.

Moliro is located in eastern Congo on Lake Tanganyika. The weekend fighting violated a 1999 Lusaka ceasefire and threatens to derail peace talks underway in Sun City, South Africa. The Kinshasa government has suspended its participation in the talks because of the fighting. Rwanda denies charges that its troops took part in the fighting in support of the rebels.

In Lusaka, Zambian President Levy Mwanawasa announced that he will host a summit of leaders of countries involved in the D.R.C. conflict. The Kinshasa government receives military and political support from Namibia, Angola, and Zimbabwe, while Congolese rebel groups are backed by the governments of Rwanda and Uganda.

For much of the past year, the warring sides had observed the ceasefire, but clashes have flared up in the east of the country in recent months. A U.N. official in Kinshasa says that the leaders will try to work out a lasting solution to the conflict, which broke out in 1998.