President Obama announced on Thursday a round of sanctions issued against 18 senior officials in the Syrian government in response to a year-old United Nations report that found the regime of Syrian President Bashar Assad had used chlorine weapons against citizens in 2014 and 2015.

“We condemn in the strongest possible terms the Syrian regime’s use of chemical weapons,” said Ned Price, spokesman for the National Security Council, in a statement Thursday. “The Assad regime’s barbaric continued attacks demonstrate its willingness to defy basic standards of human decency, its international obligations, and longstanding global norms.”