Only “four or five” U.S.-trained Syrian rebels are now in Syria to fight against the extremist group the Islamic State (IS), a top US general acknowledged Wednesday.

The original aim of the Obama administration’s $500-million training program was to recruit about 5,400 Syrians each year for three years to fight the Islamic State group.

But most among an initial group of 54 fighters who entered Syria in July were either killed, captured or fled in clashes with the al Qaeda-linked Nusra Front, prompting the current administrative review of the programme.

The head of the U.S. military’s Central Command on Wednesday told a Senate hearing on the conflict against Islamic State that he never asked for intelligence reports to be skewed to present a more positive view of military operations in Iraq and Syria.

Already integrated into the large umbrella rebel group known as Division 30, the USA official said that the fighters were allowed to visit family members for the holiday.

After Austin noted that the small number of fighters in place under the train-and-equip program, Nebraska Republican Sen.

Christine Wormuth, undersecretary of defense for policy, told senators that the US was looking at how to speed up the recruiting and screening processes. In a statement afterward, CENTCOM said: ‘There are no USA military forces on the ground in Syria, nor have we conducted any USA military training of indigenous Syrian forces in Syria.’ Any training effort of fighters in Syria is happening outside the country, CENTCOM said. Until Austin’s testimony, the Pentagon had refused for weeks to say how many fighters remained, and even after, declined to give information about the “individual disposition” of the other 49 or 50 fighters, citing operational security and their safety.

He said that the inspector general’s “investigation will play itself out (and) figure out if we did something wrong, and we will be better as a result”.

“Progress is being made”, Austin told the Senators, who appeared shocked and angry with the Pentagon’s status report. “Like Sen. McCain, I expect the committee will be kept apprised of this investigation as it continues”.

Senators challenged assertions by Austin and Wormuth, along with recent claims by Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, that the U.S.-led air campaign has been successful since it started 13 months ago. John McCain, R-Ariz., said it was further proof that the administration’s counter-IS strategy is an “abject failure”. Cook said Carter has “full confidence” in Austin.

“At the pace we’re going, we won’t reach the goal that we had initially established for ourselves”, Austin said, matter-of-factly.

“Based upon the findings, you can be assured that I will take appropriate actions”, he said. Under withering questioning from Mr. McCain, Gen. Austin repeated that he would not recommend establishing such a safe zone “at this time”.