SAN JOSE (Xinhua) -- Costa Rican President Oscar Arias hosted a ceremony for four Central American presidents on Tuesday, celebrating the 20th anniversary of the Esquipulas Two peace agreement that ended decades of civil wars in the region.

Presidents Martin Torrijos of Panama, Oscar Berger of Guatemala, Manuel Zelaya of Honduras and Antonio Saca of El Salvador came to attend the celebration. Nicaragua's President Daniel Ortega was absent due to a visit by his Brazilian counterpart, Luiz Inacio da Silva.
Arias won the 1997 Nobel Peace Prize for brokering a peace agreement during his 1986-1990 presidency. The agreement ended conflicts in Nicaragua, El Salvador and Guatemala, which killed about 300,000 people.
The agreement, signed on Aug. 7, 1987, in the Guatemalan city of Esquipulas, set out three steps to peace: disarmament, elections and economic development.
The agreement has brought peace, pluralism, greater respect for human rights and rising trade to Central American nations. Twenty years after the agreement, the region's politics are generally calm and democracy is an essential government tool