During an address to the Lao people in the country's capital, Obama pledged $90 million in a joint three-year project with the country's government to clear tens of millions of unexploded US bombs.
"Villages and entire valleys were obliterated," during US bombardments, Obama said. "Ancient plains were devastated. Countless civilians were killed. That conflict was another reminder whatever the cause, whatever our intentions, war inflicts a terrible toll, especially on innocent men, women and children."
Obama is beginning a three-day stop in Laos. He's the first US president to visit to country.
The money Obama pledged Tuesday will be spent surveying the Asian nation for some 80 million unexploded cluster bombs dropped during a secret US bombing campaign as part of the Vietnam War 40 years ago.
"The remnants of war continue to shatter lives here in Laos," Obama said. "Many of the bombs dropped never exploded. Over the years thousands of Laotians have been killed or injured, farmers tending fields, children playing. The wounds, a missing leg or arm, last a lifetime. That's why I've dramatically increased or funding to remove these unexploded bombs."
The move was welcomed by Laos President Bounnhang Vorachit as a way of strengthening mutual trust after the devastating campaign, that still maims or kills 50 people who stumble upon unexploded mines each year. In return, the Lao government pledged to ramp up assistance in locating and returning of Americans missing in war.
Efforts to find the bombs will be aided the Pentagon, who will supply records of where they were dropped.
Between 1964 and 1973, US warplanes rained more than two million tons of bombs on Laotian villages and countryside to try and cut off the Vietnamese army's supply trail.
To this day, less than 1% of the bombs have been cleared, according to US-based non-government organization Legacies of War.
US funding for clearance of unexploded ordnance and victims' assistance has steadily grown since 2010, when Congress mandated that the US government give at least $5 million for unexploded ordnance removal.
This year, Congress allotted $19.5 million, but now, for the first time, an American president has publicly recognized that the US has a responsibility to do more.
"That conflict was another reminder that whatever the cause, whatever our intentions, war inflicts terrible toll, especially on innocent men, women and children," Obama said. "Today I stand with you in acknowledging the sacrifices on all sides of that conflict. From the anguish of war, there came an unlikely bond between our two peoples."