The Clinton administration yesterday proposed a two-year, $1.3 billion aid program aimed at stemming the flow of Colombian cocaine and heroin into this country.

Secretary of State Madeleine K. Albright, who announced the package at the White House, will travel to Colombia this weekend to explain the proposal to President Andres Pastrana and consult with him on efforts to gain additional aid from multilateral banks and European allies, said her spokesman, James P. Rubin.

The aid package, if approved by Congress, would vastly increase the U.S. military equipment in Colombia. It includes a request for 30 Black Hawk helicopters and 15 UH-1N Huey helicopters, in addition to 18 Hueys that have already been sent to the Colombian Air Force to carry troops into drug-producing areas.

Senior administration officials said yesterday they do not expect the number of U.S. military personnel in Colombia, which now fluctuates between 100 and 250, to rise significantly. But they said the U.S. Agency for International Development would beef up its presence.

The administration will ask Congress to approve the bulk of the money, nearly $1 billion, in an emergency supplemental appropriation this spring, with the rest of the new funding in its fiscal 2001 budget request. Existing aid to Colombia totals $300 million, bringing the total Bogota would receive over the next two years to $1.6 billion.

The Drug Enforcement Administration estimates that cocaine and heroin exports from Colombia have increased two to threefold in recent years and supply 80 percent of the U.S. market.

Past criticism of U.S. policy toward Colombia has come from two directions. Congressional Republicans have argued that increased assistance should go to drug-fighting police rather than to the Colombian military, whose primary mission is to stop Marxist guerrillas trying to overthrow the government. Human rights groups and congressional Democrats also have warned against U.S. involvement in the guerrilla war and have raised questions about human rights abuses by the Colombian military.

The Clinton administration argues that since the guerrillas control many drug-producing areas and derive most of their income from taxing drug traffickers, the tasks of combating drugs and fighting guerrillas inevitably are intertwined, though the U.S. military aid is to be used only in drug-producing areas.

Reaction was mixed yesterday. Although a Colombian aid bill introduced by Senate Republicans last fall differs from the administration plan in several respects, its sponsor, Sen. Paul Coverdell (R-Ga.), called yesterday's announcement "good news for Colombia" and said he "look[ed] forward to working with the administration to resolve any differences between our two approaches."

Rep. Benjamin A. Gilman (R-N.Y.), chairman of the House International Relations Committee, said he welcomed the proposal but warned that the administration's "credibility on fighting drugs at the source remains in doubt" because much of the aid previously given to anti-narcotics Colombian police units was slow to arrive or defective.

On the Democratic side, Sen. Patrick J. Leahy (Vt.) expressed wariness.

"What we are seeing is a dramatic ratcheting-up of a counterinsurgency policy in the name of a counter-drug policy," he said. "The administration's purpose is to inflict enough damage to the guerrillas that they feel compelled to negotiate. That sounds appealing, but it is a costly and dangerous policy, as we saw in Central America in the 1980s."

Meanwhile, the Washington Office on Latin America, a research and policy advocacy group, said "the proposed aid package will worsen the grave crisis in Colombia, not contribute to its solution," because the administration is "directly supporting Colombian counterinsurgency efforts." Similarly, London-based Amnesty International said the plan would do little to combat right-wing paramilitary groups that commit most of the human rights abuses in Colombia and would be "tantamount to underwriting" those abuses.

The two-year aid package includes $600 million to equip, transport and provide intelligence for three U.S.-trained anti-narcotics battalions of the Colombian army; $341 million for drug interdiction efforts; $96 million for the Colombian national police; $145 million for economic development, primarily alternative crops for peasants who now supply drug traffickers; and $93 million to support judicial reforms and peace negotiations with the guerrillas.