The US military says it flew thousands of spy flights over Colombian jungles trying to find and free three US Defense Department contractors every day since their 2003 kidnapping. In the end, it was a daring operation by Colombian military intelligence agents that finally rescued the men from leftist rebels. Until this week's rescue, some US government officials despaired that freedom might never come for Tom Howes, Marc Gonsalves and Keith Stansell. Some counterterror, military and diplomatic officials familiar with Bush administration efforts to secure their release questioned whether enough was being done. On Thursday, Col. William Costello, spokesman for the US Southern Command, said that the command made 3,600 intelligence, surveillance and reconnaissance flights; followed up on 175 intelligence leads and spent $250 million trying. "We've been actively searching for these guys every day for the past 5Â½ years," Costello said. FBI spokesman Richard Kolko said the bureau sent crisis negotiators and investigators on "countless trips to Bogota" since the kidnapping. One official said a Defense Intelligence Agency cell that primarily works to track captured or missing US troops has been working on the case of the civilian contractors. Another said US intelligence eventually located the hostages. A third said the US Special Operations Command helped with surveillance that positively located the hostages within the last year using satellites, aircraft and ground reconnaissance and had tracked them since. All three spoke on condition of anonymity because they were not authorized to speak on the record, and the Bush administration was adamant about giving the Colombian government credit for the rescues of the Americans, French-Columbian politician Ingrid Betancourt and 11 Colombian troops. "This was a Colombian-planned and Colombian-executed operation," State Department spokesman Sean McCormack told reporters. "We were in a supporting role." Officials have said the US and Colombian governments have known the location of the hostages a number of times over the years and planned several rescue missions. But they did not attempt them because of the difficulty of the jungle terrain and the risk that the hostages could be killed. Finally, it was a trick by Colombian spies that persuaded rebels to hand over the hostages Wednesday. Colombian Defense Minister Juan Manuel Santos said military intelligence agents infiltrated the guerrilla ranks and led the local commander in charge of the hostages to believe they were being taken to the guerrillas' supreme leader. The reluctance of US officials to highlight the US role may be a reflection of American politics. Congressional support for Plan Colombia, the multibillion dollar US aid package to Colombia to help it fight its war on drugs and the insurgency, has rested heavily on promises that no US troops would be put at risk and drawn into a jungle war with rebels, said George Withers, senior fellow with the Washington Office on Latin America, a human rights advocacy organization. Withers served 25 years as an aide on Capitol Hill. Congress has capped the number of American troops and contractors to explicitly limit the extent of US involvement there to under 1,500 people, which indicates Congress' wariness about US military involvement there, Withers said. Several officials charged last year that the White House was reluctant to pursue a rescue forcefully or to press the Colombian government to step up its own efforts. That infuriated some career government negotiators, frustrated the men's employer, Northrop Grumman, and baffled the contractors' relatives who could not understand why the men languished so long. At one point, the Justice Department warned Northrop Grumman against sending backpacks of sneakers, medication and other items to the hostages, according to several people familiar with the conversations. The government cautioned that if the items ended up in the hands of rebels, it would violate the USA Patriot Act's ban on providing material support to terrorists, the people said. Several current and former US officials said the Bush administration failed to engage in routine negotiations or take other diplomatic steps of the kind used in similar hostage situations. That included deploying Foreign Emergency Support Teams - Washington-based special squads comprising counterterror experts and crisis workers from the departments of State, Justice and Defense and the 16 intelligence agencies. The State Department said the teams were not deployed because there was insufficient information about the hostages' location or whether they were alive. Some officials also charged that intelligence gathering on the hostages was limited by the administration's focus on disrupting terrorists in Iraq and elsewhere in the Middle East. In a Jan. 23, 2007, letter to Northrop Grumman vice president James F. Pitts, National Security Adviser Stephen J. Hadley said the Bush administration had "increased resources devoted to this issue in Bogota," including "fully leveraging all intelligence and available national resources." A copy of the letter was obtained by the AP.