The "human tragedy" of illegal immigrants dying and being abused as they attempt to enter the United States will continue until the federal government acknowledges the important economic role undocumented workers play, Sen. John McCain (search) told Hispanic leaders Saturday.

"It is in our national interest to bring the 8 to 12 million undocumented immigrants out of the shadows and allow them an opportunity to become citizens of this great nation," McCain said at the annual conference of the National Council of La Raza (search), a civil rights group and political think tank dedicated to promoting Hispanic issues.

The Arizona Republican said federal policy and border enforcement have failed to alleviate the deaths of migrants crossing the sweltering Southwest deserts and the violence of smugglers who often hold immigrants for ransom once they reach America.

An example of the government's wrongheaded approach, McCain said, is its recent introduction of unmanned aerial vehicles in Arizona that use thermal and night-vision equipment to help Border Patrol agents spot illegal immigrants (search).

"That ignores the fundamental problem," he said. "Where there's a demand, there's a supply ... There's a demand for people to fill jobs that Americans won't do."

Last year, McCain proposed legislation for a guest-worker program that would allow immigrants to work in the states for three years and then apply for legal permanent residency. Undocumented immigrants already working in the United States would have to wait another three years on a restricted visa before applying for permanent residency.

McCain on Saturday referred to his plan and other guest-worker proposals, including one by President Bush.

"These are all good proposals but we won't act because we're in an election year," he said. "The human tragedy taking place on our streets and the Southwestern border must be stopped."

McCain also spoke about the war in Iraq, stressing the importance of success in the June 30 transfer of power to the Iraqi government.

"We cannot afford to fail," he said. "We have sent our most precious blood and treasure so that (Iraqis) might have the same opportunities that we do."

He said successful democracy in the Middle East would curb terrorism by teaching children that America is not the enemy.