US President Donald Trump has reversed his administration's decision to cut funding for the Special Olympics, saying the competition for people with intellectual disabilities is "incredible."

"The Special Olympics will be funded," Mr Trump told reporters at the White House, saying he was "overriding" his administration.

"I've been to the Special Olympics, I think it's incredible," he said.

He was speaking after Education Secretary Betsy DeVos caused an uproar when she said the government was axing $18 million in funding. 

The cut was part of a proposed hefty 10% reduction in overall federal education spending - a saving of $7 billion.

"We had to make some difficult decisions with this budget," Ms DeVos told a House appropriations subcommittee hearing on Tuesday.

When she acknowledged she did not know how many American children would be affected by the cuts, House Democrat Mark Pocan provided the figure - 272,000.

The Special Olympics, founded by president John F Kennedy's sister Eunice Kennedy Shriver in 1968, has grown into a global movement, providing competition for children and adults with intellectual disabilities.

The organisation is largely funded by corporate and private donations. 

The US funds had been earmarked for Special Olympics education programs at 6,500 schools, where activities have shown to increase inclusion and reduce bullying.

Ms DeVos was grilled on Capitol Hill about the plan with members of Congress describing it as cruel, reckless and appalling.

Democratic congresswoman Barbara Lee called the Special Olympics cuts "appalling."

With the outcry growing, Ms DeVos on Wednesday insisted the Department of Education remains "focused every day on raising expectations and improving outcomes for infants and toddlers, children and youth with disabilities."

She defended the move by saying that the Special Olympics raises more than $100 million philanthropically every year, and that the government cannot fund every worthy programme, particularly ones that enjoy robust support from private donors.

The Special Olympics said however that the money is critical to protecting and increasing access to services for people with intellectual disabilities. 

The organisation urged congress to remain vigilant against any erosion of provisions that have made a substantial difference in people's lives.

Special Olympics chairman Timothy Shriver expressed disappointment with the proposal, saying the organisation does critical work in schools to help educate youths "about the importance of an inclusive mindset to the future of the country."

The latest Special Olympics World Games were held last week in Abu Dhabi, where team Ireland took home a haul of 86 medals.

Additional reporting: Brian O'Donovan