Defense Secretary Jim Mattis, left, Secretary of State Rex Tillerson, President Trump and others listen as Chinese President Xi Jinping speaks during a bilateral meeting in Palm Beach, Fla., on Friday. (Alex Brandon/AP)

The United States is prepared to again take action against the Syrian government if it continues to use chemical weapons and barrel bombs, White House press secretary Sean Spicer said Monday. The use of barrel bombs — crude munitions often forbidden by international law — has become a near daily occurrence in war-torn Syria, so taking action each time one is dropped would mark a dramatic shift in strategy and would quickly escalate U.S. involvement in Syria.

Although Spicer lumped barrel bombs in the same category as chemical weapons on three separate occasions during a Monday briefing with reporters, he later insisted that his comments should not be interpreted as a change in U.S. policy.

White House press secretary Sean Spicer said "further action will definitely be considered by the United States" if the Assad government uses chemical weapons again, during his daily briefing on April 10 at the White House. (Reuters)

“Nothing has changed in our posture,” Spicer said in a statement late Monday afternoon. “The president retains the option to act in Syria against the Assad regime whenever it is in the national interest, as was determined following that government’s use of chemical weapons against its own citizens. And as the president has repeatedly made clear, he will not be telegraphing his military responses.”

Spicer’s first mention of barrel bombs came in the opening minutes of the briefing, when he reviewed Friday’s attack on a Syrian military airfield, the first direct U.S. assault on Syrian President Bashar al-Assad’s regime since a civil war began nearly six years ago. The Trump administration has said that the strike was in retaliation for a chemical attack earlier that week that killed scores of civilians, including many children.

“The sight of people being gassed and blown away by barrel bombs ensures that if we see this kind of action again, we hold open the possibility of future action,” Spicer said.

Later in the briefing, Spicer reiterated this stance, saying: “When you watch babies and children being gassed and suffer under barrel bombs, you are instantaneously moved to action. I think this president has made it very clear that if those actions were to continue, further action will definitely be considered by the United States. We continue to urge further the world community to join us . . . in both stopping the deterrence and proliferation of those, use of those weapons, but then further trying to create a political environment that’ll result in new leadership.”

Still later, a reporter pressed Spicer to clarify his comment, asking whether “conventional warfare” constitutes a red line for the White House, along with chemical warfare.

“Look, I think the president has been very clear that there are a number of lines that were crossed last week,” Spicer replied. “We saw that in the last administration. They drew these red lines and then the red lines were run over. I don’t think you’re going to see the same play. I think what not just Syria but the world saw last week is a president that is going to act decisively and proportionally and with justification when it comes to actions like that. . . . The answer is, is that if you gas a baby, if you put a barrel bomb in to innocent people, I think you can — you will — you will see a response from this president. That is unacceptable.”

Barrel bombs are oil drums packed with explosives and nails or other shrapnel that are rolled out of helicopters. Crude and imprecise, these bombs have landed not only on rebel forces but also on Syrian markets, hospitals, schools and other areas filled with civilians, killing thousands. The United Nations Security Council has condemned the regime’s use of these bombs and ordered Assad to stop using them. Assad denies that the munitions are being used, but the Syrian Network for Human Rights estimates that the Syrian government dropped 12,958 barrel bombs in 2016, resulting in the deaths of 653 civilians, including 166 children and 86 women.

The White House’s messaging on Assad’s future has also been vague, with Spicer saying Monday that he couldn’t “imagine a stable and peaceful Syria where Bashar al-Assad is in power” and that the United States hopes to create “the environment for a change in leadership.” Spicer would not directly answer a reporter who asked if Trump considers Assad a war criminal, saying that such a question should instead by answered by an international court. When asked whether the United States could defeat the Islamic State terrorist group with Assad still in power, Spicer responded, “Yeah. Sure.”

The U.S. missile strike heightens the risk of direct confrontation with Russia and Iran, which back Assad and condemned the U.S. intervention. Secretary of State Rex Tillerson is headed to Russia this week, and the U.S. special envoy for Syria will be in Washington on Tuesday for meetings at the White House with State Department and national security officials.

Spicer declined to say whether Tillerson would threaten Russian officials with more sanctions.

“I think we need to remind them of the commitments that they’ve made and the commitments that Syria’s made,” Spicer said. “There’s no question who acted in this case and what Syria did. And I think that we need to make sure that Russia fully understands the actions that Assad took, the commitments that Syria has made — and Russia has equally agreed to those same — understanding. So getting them back on the same page, first and foremost, would seem the logical step.”

During the briefing, Spicer said all 59 Tomahawk missiles hit their intended targets, “showing America’s power and the military’s accuracy, which is just a small representation of our military’s overall capability and a fraction of what this president will continue to build up the military to be throughout his administration.” Spicer said the attack destroyed 20 percent of the Syrian government’s fixed-wing aircraft and its fueling operation.

Spicer repeatedly ducked pointed questions about the president’s position, because “he’s going to keep his cards close to the vest.” On the campaign trail, Trump would often avoid questions about military intervention or his strategy for defeating the Islamic State by saying that he did not want to reveal his plans to the enemy. But ahead of the strike in Syria, a Pentagon spokesman, Capt. Jeff Davis, said, “Russian forces were notified in advance of the strike using the established deconfliction line” in an effort to “minimize risk to Russian or Syrian personnel located at the airfield.”

“One of the things that I don’t want to start doing . . . is say, ’If you do this, this is the reaction that you’re going to get,’ ” Spicer said. “The president’s made very clear throughout his time in the campaign, through the transition and now as president, that he’s not going to telegraph a response to every corresponding action, because that just tells the opposition or the enemy what you’re going to do and whether that response is worth taking. The president’s going to be very clear that he’s going to keep his cards close to the vest. But make no mistake, he will act.”

Dan Lamothe contributed to this report.