A high-ranking US general confirmed Friday that the US government has suspended covert weapons deliveries by the CIA to Syrian rebels.

US President Donald Trump's decision to end the programme to arm and train so-called moderate Syrian rebels, first reported by the Washington Post on Wednesday, was greeted as "long-awaited, excellent" news.

General Tony Thomas, commander of US special forces, said the move was not a concession to Russia.

It is "absolutely not a sop to the Russians," Thomas said at a security conference in Aspen, Colorado. "It was, I think, based on an assessment on the nature of the programme, what we're trying to accomplish, the viability of it going forward."

The CIA began the covert programme in 2013 under president Barack Obama. The agency has been equipping the moderate rebels with light weapons and munitions. But numerous groups have complained in recent months of receiving little help from the outside.

Government officials told the Washington Post that Trump's decision to stop the programme reflected his interest in finding ways to cooperate with Russia. Moscow is one of Syrian President Bashar al-Assad's most important backers.

The decision to suspend the programme was made a month ago, according to the Post, preceding the US president's meeting with Russian President Vladimir Putin during the Group of 20 summit in Hamburg, Germany two weeks ago.

Trump and Putin agreed to a ceasefire deal covering south-western Syria during the summit. Government officials told the Post the decision to stop the weapons deliveries was not a condition of the ceasefire.