The U.S. Department of Defense has spent nearly $400 million, or $2 million per fighter, on its failed programme that sought to train and equip Syrian rebel forces to fight the Islamic State (ISIS) militants, according to the USA Today.

The paper said the Pentagon abandoned the programme last month after it had already spent $384 million for the project alone. The training programme yielded only dismal results, officials said.

Even with the huge amount of money spent, the U.S. was only able to train and field 200 fighters. The programme had aimed to graduate 3,000 trained and equipped New Syrian Forces fighters in 2015 to help protect their villages from ISIS attacks.

"It's clear to everyone now that this initial programme was a failure," said Sen. Claire McCaskill, D-Montana, a member of the Armed Services Committee. "My hope is that Pentagon leaders have taken the lessons of this failure to heart as they pursue a different approach in Syria."

Armed Services Committee member Rep. Jackie Speier, D-California, slammed the Pentagon for not ending the programme sooner. "As we've discovered, the Syria train and equip process was ill thought out and spectacularly wasteful. Congress should demand periodic reports by the military when it becomes clear it is not meeting its goals. It borders on malfeasance that so much money was spent before the plug was pulled."

Of the 180 Syrians vetted, trained and equipped, 145 fighters remain in the programme, said the report. Of those 145 fighters, 95 are in Syria.

Reacting to the findings, Pentagon officials claimed that the actual cost of the training programme is far lower or around $30,000 per trainee and not $2 million.

"Our investment in the Syria train and equip programme should not be viewed purely in fiscal terms," Navy Cdr. Elissa Smith, a spokeswoman, said in her email to the news outfit.

"The vast majority of the funds paid for weapons, equipment and ammunition, some of which the U.S.-led coalition still has in storage,'' she said, adding that some of those trained fighters have been calling in air strikes, and ammunition designated for the trainees has been given instead to other forces fighting ISIS.

In the document outlining the programme's $501 billion budget, it said $204 million was supposedly spent for ammunition, $77 million on weapons, $62 million on mobility services, $47 million on other services, $46 million on construction, $40 million on strategic lift/shipping, $13 million on communications, and $6 million on facilities and maintenance.

The spending figures for the failed programme, broken down into nine categories, indicated that the U.S. military earmarked tens of millions of dollars to build training camps that were rarely if ever used for flights to transport the trainees from their homes to training sites and battlefields, according to USA Today.

The Pentagon said it will still give equipment and weapons to the leaders of vetted groups of rebels who are already fighting ISIS "so that over time they continue to re-claim territory.''