Venezuelan President Hugo Chavez said Sunday he is putting relations with Colombia "in the freezer" after its president ended the Venezuelan leader's role mediating with leftist rebels in the neighboring country. The announcement drew a strong rebuke from Colombian President Alvaro Uribe, who said Chavez's actions suggest he wants to see a "terrorist government" run by leftist rebels in Bogota. Uribe also suggested Chavez might be looking to stir up conflict to boost his image ahead of a referendum on constitutional changes next weekend. The spat was the bitterest yet between Chavez and the US-allied Uribe, who have sought to cultivate cordial ties despite deep ideological differences. It could have serious economic consequences. The two countries are major commercial partners, with $4.1 billion in trade last year, about two-thirds of that in Colombian exports to Venezuela. Neither leader announced any concrete plan, but Chavez said economic relations will be hurt as a result of Uribe's actions, which he called "a spit in the face." "I declare before the world that I'm putting relations with Colombia in the freezer because I've completely lost confidence with everyone in the Colombian government," Chavez said in a televised speech. He said he was convinced Uribe's government does not want peace. Chavez was responding to Uribe's decision Wednesday to end his role mediating preliminary talks with Colombian guerrillas, aimed at negotiating a prisoner swap to free rebel-held hostages, including three Americans. Uribe said through a spokesman that Chavez broke the conditions of his involvement by directly contacting the chief of Colombia's army. On Sunday, Uribe appeared to question Chavez's motives in the process. "Your words, your attitudes, give the impression that you aren't interested in peace in Colombia, but rather that Colombia be a victim of a terrorist government of the FARC" rebels, Uribe said at a townhall meeting in the town of Calamar. Uribe suggested Chavez's harsh criticism of his government might be part of an attempt to build public support before Sunday's referendum on changes to Venezuela's constitution, which would allow Chavez run for re-election indefinitely. Uribe also suggested Chavez might be trying to spread his socialist ideology beyond Venezuela's borders, an effort he said would "make no headway" in Colombia. The confrontation marks a sharp change for two leaders who have often appeared together smiling. Just last month, the two inaugurated a natural gas pipeline between their countries, pledging to boost ties. But addressing Cabinet ministers and military officials on Sunday, Chavez warned Colombian businesses in Venezuela and Venezuelans in Colombia to "be alert." "Commercial relations, all of that is going to be harmed. It's lamentable," he said. Chavez began mediating between the Colombian government and rebels in August, in a new push to free hostages held by the Revolutionary Armed Forces of Colombia, better known as FARC. Prisoners include three US military contractors and Ingrid Betancourt, a French-Colombian seized in 2002 while campaigning for Colombia's presidency. Chavez said he was particularly irked that Uribe announced his decision to end his mediation role through official statements, instead of contacting the Venezuelan leader directly. "I think Colombia deserves another president, it deserves a better president," he said. The diplomatic spat comes amid another dispute with Spain that could affect Spanish businesses with major investments in Venezuela. Chavez has demanded Spanish King Juan Carlos apologize for telling him to shut up publicly during a recent summit in Chile. Chavez said the situation with Colombia is similar: "It's like the case of Spain: Until the king of Spain apologizes, I'm freezing relations with Spain." Uribe replied: "President Chavez, the truth is you can't set fire to the continent like you do, talking one day against Spain, the next day against the United States. ... You can't mistreat the continent, lighting it up like you do, and speaking of imperialism when you - based on your budget - want to create an empire."