SAN SALVADOR (Reuters) - Mexican President Felipe Calderon on Tuesday added his voice to regional condemnation of Colombia's military strike on rebels inside Ecuador, and called on the two countries to resolve the problem peacefully.

"We coincide in the rejection of any action that constitutes a violation of territorial sovereignty," Calderon said after a meeting with Salvadoran President Tony Saca in which the two leaders discussed the crisis.

Colombia bombed neighboring Ecuador's territory on Saturday to kill a senior leftist FARC guerrilla, leading Ecuador's ally Venezuela to warn that war could break out in the region. Both Ecuador and Venezuela have mobilized troops.

Mexico's criticism of Colombia came after Brazil condemned the bomb attack on Monday and called on Bogota to offer an explicit apology.

Nicaragua has also condemned Colombia's killing of the rebel commander, and former Cuban President Fidel Castro called the incident a "monstrous crime."

Calderon said Mexico would try to help Colombia and Ecuador resolve the crisis.

"We will spare no effort so that the Colombian and Ecuadorean governments normalize relations as soon as possible through dialogue and diplomatic channels," Calderon said.

Calderon may meet with Colombian President Alvaro Uribe at a regional summit being held in the Dominican Republic on Thursday and Friday, Mexican state news agency Notimex reported.

Dominican government sources have said both Venezuelan President Hugo Chavez and Ecuadorean President Rafael Correa might attend the summit.