Barrios let Valle know, that in case he planned to continue this course, he would see to it that the Guatemalan government would support José María Medina from Honduras in overthrowing Ponciano Leiva.

The government of El Salvador insisted on González's goodwill and a conference at the Volcán Chingo was agreed on, at which, with mediation of Marco Aurelio Soto, an agreement was signed.

Barrios was convinced, González remained the actual head of state in El Salvador and insinuated him holding public speeches, as well as committing hypocrisy and treason.

On March 20, 1876, the Guatemalan Secretary of War, Jose Maria Samayoa, declared all official relations with El Salvador as terminated, asserted that on March 27, 1876, troops from El Salvador had invaded Guatemala, declared war and gave Barrio absolute power for defending Guatemala's dignity.

Between April 17 and 19 1876, General Gregorio Solares had the troops of generals Brioso, Delgado, Sanchez and Espinosa beat and thus controlled the Departments San Miguel an La Union, threatening the Departments San Vincete as well as Usulután and even the official residence of President Valle, cutting off the Salvadorian government from essential resources.

There were enough soldiers to defend Ciudad San Vecente, but the government of El Salvador gave orders for the garrison to troop in the capital.

During the siege of Atiquizaya, according to the American historian Hubert Howe Bancroft, Barrio had 900 bombs thrown, subsequently marching into Ahuachapan and the following day into Cahlchuapa, where peace talks took place.