The United States on Monday said the continued violations of humanitarian law in Syria are being enabled by flow of arms and foreign fighters to the Assad regime. "We are concerned that [the] abuses are being enabled by the continued flow of arms and foreign fighters to the Assad regime from outside Syria, including weapons shipments from Iran, in violation of sanctions adopted by the U.N. Security Council," State Department spokeswoman Jennifer Psaki told reporters. "We are conscious of the increasing threat the conflict in Syria is posing to the interests of neighboring states, including the serious risk of the proliferation of Syria's chemical weapons to non-state actors, in violation of U.N. Security Resolution 1540," Psaki added.