The additional fund was announced after a meeting between the US Ambassador in Sri Lanka, Atul Keshap, and Minister of Rehabilitation, Resettlement and Hindu Religious Affairs D M Swaminathan.
In total, the United States has dedicated over USD 43 million for demining assistance in Sri Lanka since 1993.
"I support Minister Swaminathan's vision of making Sri Lanka mine-impact free by 2020," Keshap said.
"As the world's largest donor of global demining efforts, the United States is committed to addressing the land mine problem in Sri Lanka," he said in a statement.
"The United States will continue to work with President Sirisena, Prime Minister Wickremesinghe, Minister Swaminathan, and the people of Sri Lanka to help clear the remaining areas," Keshap said.
The US is also working to boost Sri Lanka's own demining capacity through training for mine disposal units in the Sri Lankan military, including the Mine Detection Dog programme.