A top Cambodian demining official slammed US President Barack Obama’s widely heralded pledge to increase demining aid to Laos on Tuesday, faulting the US for what he characterised as its “marginal assistance” to Cambodia’s demining efforts.

In a speech at the 2016 ASEAN Summit in Vientiane on Tuesday, Obama pledged $90 million in demining aid to Laos over the next three years, prompting Heng Ratana, director-general of the Cambodian Mine Action Centre (CMAC), to immediately take to social media to decry the aid package.

“This is very unfair and injustice for Cambodian people!” Ratana wrote in a status update, published late that same night.

Ratana claimed almost 3 million tonnes of bombs were dropped in Cambodia, killing 500,000 people. (The actual tally of US bombs and the casualties they caused is still disputed by historians.)

“However, Cambodia remains receiving a marginal assistance”, Ratana wrote.

The US military engaged in secret bombings of Cambodia and Laos during the Vietnam War from 1964 to 1973. Many bombs failed to detonate on impact, leaving the countryside of Cambodia, Laos and Vietnam riddled with unexploded ordnance (UXO).

Yale professor and historian Ben Kiernan has estimated that closer to 500,000 tonnes of bombs were dropped in Cambodia, with about 50,000 to 150,000 Cambodians killed.

By comparison, Kiernan accepts the conventional estimate – reiterated by Obama on Tuesday – that over 2 million tonnes of bombs were dropped on Laos during that same period, making it the most heavily bombed country, per capita, in history.

However, this did little to assuage Ratana.

“They dropped on three countries but gave aid to two, and don’t give to one”, Ratana said in an interview yesterday. “We don’t have power, as the money is in their pocket, but we will tell about our need.”

A spokesman for the US Embassy in Cambodia, however, said that the US government is “one of the largest donors” to Cambodia in terms of demining aid, currently contributing $5.5 million in annual support.

“The United States has been working to address explosive remnants of war in Cambodia for more than 20 years and has invested well over $100 million to remove and safely dispose of landmines and unexploded ordnance”, spokesman Jay Raman said yesterday.

Ratana, however, declined to address the US’s decades of assistance. He also dismissed the notion that his remarks could have a negative impact on future funding.

“I think that US President Obama understands about the moral obligation, and he should provide justice,” he said.

The Cambodian Mine Action and Victim Assistance Authority, meanwhile, took a more diplomatic approach, congratulating Laos on the new deal and acknowledging the past assistance of the US government, while expressing hope to strengthen cooperation in the future.