In an interview broadcast ahead of his meeting with President Barack Obama, Putin made a point of noting the Pentagon's recent admission that an effort to train 5,000 Syrian rebels had yielded only four or five fighters.
He also said the US "provision of military support to illegal structures runs counter to the principles of modern international law and the United Nations charter."
The interview with the US networks CBS and PBS will be broadcast this evening in the United States. The Kremlin earlier in the day released an excerpt of the interview.