The presidents of Venezuela and Ecuador kept the pressure on Colombia as they arrived in the Dominican capital late Thursday. The Rio Group summit was to have focused on energy and other issues, but the diplomatic crisis in the Andes now has center stage.
Ecuadorean President Rafael Correa told reporters he wants Colombian President Alvaro Uribe to apologize for Saturday's military attack against leftist Colombian rebels in Ecuadorean territory, as well as his "formal and firm commitment" that Colombia will never "violate" the sovereignty of another country.
On his arrival in Santo Domingo, Venezuelan President Hugo Chavez made jibes at Colombia and the United States, which has supported the Andean nation with more than $4 billion in counterinsurgency and anti-drug aid since 2000.
"The U.S. empire has taken over Colombia," Chavez said.
Chavez claimed the strike that killed Raul Reyes, a top leader of the Revolutionary Armed Forces of Colombia, or FARC, was "planned and directed" by the U.S. Later, he said he had information that "gringo soldiers" participated in the attack, but provided no evidence to back the claim.
Earlier this week, a spokesman for the U.S. Southern Command, Jose Ruiz, would neither confirm nor deny that the U.S. military took part in the attack that killed Reyes and 23 other guerrillas.
Chavez has ordered thousands of troops and tanks to Venezuela's border with Colombia and threatened to slash trade and nationalize Colombian-owned businesses. Ecuador has also sent troops to the border.
Uribe, who is hugely popular among Colombians for efforts to crack down on the FARC, which finances itself through kidnapping and drug trafficking, declined to comment on the crisis as he arrived for a meeting with Dominican President Leonel Fernandez.
Earlier, Uribe defended the attack as necessary given Ecuador's inaction against Colombian rebel camps in its territory. Colombia complains that rebels take refuge across the border in neighboring countries and has accused their leftist leaders of backing the rebels - a claim the leaders deny. Uribe has said he won't send Colombia troops to the border.
Friday's opening of the presidential summit will mark the first face-to-face encounters between Uribe, Chavez and Correa since the international crisis began.
The crisis widened Thursday when Nicaragua broke off relations with Colombia over the attack inside Ecuador. Nicaraguan President Daniel Ortega, who was also expected to attend the summit, is an ally of Chavez and Correa.
Before the presidents began arriving here Thursday night, foreign ministers from a host of countries drafted a statement saying national sovereignty must be respected. The draft, to be submitted to the Latin American presidents on Friday, mirrors one this week from the Organization of American States, said Chilean Foreign Minister Alejandro Foxley.
Mexican President Felipe Calderon said he hopes that "we can have a dialogue in a sensible way to find a peaceful solution" at the summit. Calderon added that he doubted one would be found quickly.
Uribe has refused to rule out future military incursions into Ecuador or Venezuela, saying he first needs assurances from Correa and Chavez that they are not harboring rebels.
In Ecuador, Security Minister Gustavo Larrea said the army captured five suspected FARC rebels on Thursday. The suspects were nabbed "a few meters from the Colombian border," in the general area where the raid took place, Larrea told a news conference.