Venezuela on Sunday night rejected US requests to resume cooperation in the war on drugs, insisting it has made progress despite an alleged fourfold gain in the amount of Colombian cocaine passing through its territory. In the latest barb-trading over the issue, President Hugo Chavez called White House drug czar John Walters "stupid" for saying drug trafficking through Venezuela has soared in recent years. Chavez even warned that the US ambassador could be asked to leave the country. Walters has been attempting for weeks to meet with Venezuelan officials while urging renewed cooperation with the US Drug Enforcement Administration. Chavez suspended cooperation in August 2005, accusing DEA agents of espionage. On Sunday, Venezuela's Foreign Ministry released a statement dismissing US attempts to renew drug talks as "useless and inopportune," saying US officials should focus instead on slashing demand for drugs at home. "The anti-drug fight in Venezuela has shown significant progress during recent years, especially since the government ended official cooperation programs with the DEA," the statement said.