Mississippi Democrat Gene Taylor, who sponsored the amendment and criticised President Clinton's plan, said the Colombian Government had made its own citizens with high school diplomas ineligible for military service.
The plan, backed by President Bill Clinton, is intended to help train and equip Colombia's military and police in their fight against drug traffickers who provide 80% of the heroin and cocaine sold in the US.
The Colombian army will receive 45 helicopters, and peasants who supply the drug traffickers will be given aid to develop alternative crops.
Cash will also be earmarked to support peace negotiations with the Marxist guerrillas who control much of the drugs trade.
But critics of the plan - both Republicans and Democrats - warn that it risks dragging the US into Colombia's civil war.
Military limit
To ease concerns that the plan could lead to a Vietnam-like
involvement in Colombia's civil unrest, House members passed an amendment
to limit US military personnel deployed in Colombia at any one time to 300, unless more are needed for a rescue mission.
Mississippi Democrat Gene Taylor, who sponsored the amendment
and criticised President Clinton's plan, said the Colombian Government had made its own citizens with high school diplomas ineligible for
military service.
"I expect they want American kids to fight in the war they won't fight and American taxpayers to pay for a war they won't pay for," Mr Taylor said.
'Protect our nation'
House Speaker Dennis Hastert made a rare floor speech urging his colleagues to approve the plan, as it met resistance from a group of Democrats and conservative Republicans.
The Illinois Republican is a chief backer for Washington to join a $7.5bn international effort to shore up the government of President Andres Pastrana in the face of Latin America's longest-running civil conflict.
White House drug policy director Barry McCaffrey said the plan is "designed to protect our nation from the flow of Colombian heroin and cocaine" that he said contributes to 52,000 US deaths annually from illegal drugs.
"Colombia is too close geographically for us to pretend we are not affected by its growing drug production, violence and chaos," Mr McCaffrey said.
Before the plan is put into effect, it must win approval from the Senate - where criticisms are the same and the vote may be closer.
President Pastrana has said his government will wage a diplomatic offensive in Washington to try to ensure that Congress approves the aid.