North Korea's authoritarian leaders were to blame for the famine that killed hundreds of thousands in the 1990s, experts told U.N. investigators probing possible crimes against humanity in the secretive nation.

Speaking at a hearing in Washington, two American experts said former leader Kim Jong Il's regime continued acquisitions of fighter jets and failed to increase food imports to make up for a shortfall in food.

Andrew Natsios, a former administrator of the U.S. Agency for International Development, said food was diverted from the northeast, which is home to many people deemed disloyal to the regime. He also said Pyongyang barred international aid in that region for two years but relented when the U.N. threatened to end food distributions across the country.

Natsios said he did not think the North's leadership deliberately caused the famine, “however, once the famine started they knew about what was going on and they chose not to take action to protect their population because their first objective is (the regime's) survival, not feeding their people.”

The U.N. commission of inquiry, chaired by Australian judge Michael Kirby, is empowered by the world body to seek full accountability, and responsibility for the famine is one line of inquiry. North Korea, which denies right abuses, is not cooperating and has refused access to the investigators.

Marcus Noland, an expert on North Korea's economy, estimated that between 600,000 and 1 million people died in the famine, which he said began before the floods starting in 1995 that Pyongyang blamed for the catastrophe. He said after aid flowed in, the North reduced its commercial imports of food.

If North Korea had spent between $100 million and $200 million more on annual imports, it could have averted the shortfall in food. “Even during the famine, the North Korean government had the resources at its disposal, if it chose to do so, to maintain imports and avoid this calamity,” Noland said.

Natsios said in the North's highly centralized system, the dictator Kim _ he died in 2011 _ was ultimately responsible, but some 2,000 elite officials around his family may have made policy decisions that they knew could lead to deaths.

Based on research from officials who fled the country, he estimated that between 40 percent and 70 percent of the food aid was diverted to the military, but he attributed that not to orders from Pyongyang, but to the regime losing control of the situation.

The commission has also taken testimony from North Korean defectors in South Korea, Japan and London. It will present its report to the U.N. Human Rights Council next March.

It's not yet clear what actions the world body could then take. Even if the panel concludes crimes against humanity have been committed, a referral to the International Criminal Court appears unlikely, as it would require the approval of the U.N. Security Council, where the North's longtime benefactor, China, has a veto. (AP)