President Trump is signaling a more aggressive approach toward Syria, saying on Wednesday reports of a deadly gas attack by forces loyal to  Bashar Assad had “crossed a lot of lines” and moved him to rethink his strategy.

At a joint press conference on Wednesday at the White House with Jordan’s King Abdullah II, Trump indicated that the Syrian leader had gone too far with an attack this week that killed dozens of his own people and injured scores more, including women and children.

“It crossed a lot of lines for me,” Trump said. “When you kill innocent children, innocent babies, little babies with a chemical gas that is so lethal that people were shocked to hear what gas it was, that crosses many lines beyond the red line. Many, many lines.”

“I will tell you, what happened yesterday is unacceptable to me,” Trump added.