U.S. President Donald Trump on Monday promised quick, forceful action in response to the weekend's lethal suspected chemical weapons attack on Syrian civilians, appearing to suggest a potential military response.
Trump told a meeting with military leaders and national security advisers he would make a decision on a response by Monday night "or very shortly thereafter," adding that the United States has "a lot of options militarily" on Syria.
"But we can't let atrocities like we all witnessed [happen]. We can't let that happen in our world, especially when we're able to, because of the power of the United States, the power of our country, we're able to stop it," he said.
The attack late on Saturday in the city of Douma, near Damascus, killed at least 60 people and injured more than 1,000 at several sites according to a Syrian aid organization.
Initial U.S. assessments have been unable to determine conclusively what materials were used in the attack and could not say with certainty that Syrian President Bashar Assad's government forces were behind it.
Trump said the U.S. was "getting more clarity" on who was responsible for the attack.
U.S. officials said Washington was weighing up a multinational military response.
For the second time in less than 24 hours, Trump and French President Emmanuel Macron spoke by telephone to coordinate their response, the White House said.
Macron and Trump again reiterated their desire for a "strong reaction" from the international community, Macron's office said.
Asked at a cabinet meeting earlier on Monday if Russian President Vladimir Putin bore any responsibility for the attack, Trump said, "He may, yeah, he may. And if he does, it's going to be very tough, very tough."
U.S. Ambassador to the United Nations Nikki Haley told the U.N. Security Council on Monday that Washington would mount a response. She criticized Moscow for backing the Assad regime, saying Russia's hands "are covered in the blood of Syrian children."
"Chemical weapons have once again been used on Syrian men, women and children," Haley said. "History will record this as the moment when the Security Council either discharged its duty or demonstrated its utter and complete failure to protect the people of Syria. Either way, the United States will respond."
Trump had sought warmer relations with Russia, but on Sunday criticized Putin by name on Twitter and castigated Russia and Iran for backing "Animal Assad."
Russia said it had warned the United States of "grave repercussions" if it carries out an attack against Syrian government forces.
The Syrian government and Russia have denied involvement in the attack.
Britain and the United States agreed on Monday that the attack resembled previous chemical attacks by Assad's government, but neither country gave details of what kind of chemical might have been used or how the attack was carried out.
"The images, especially of suffering children, have shocked the conscience of the entire civilized world," said White House spokeswoman Sarah Sanders. "Sadly, these actions are consistent with Assad's established pattern of chemical weapons use."
The U.S. fired missiles on a Syrian air base a year ago in response to the killing of dozens of civilians in a sarin gas attack in an opposition-held town. The missile strikes did little long-term damage to Syrian government forces and Assad's position has only become stronger with Iranian and Russian support.
The stakes are higher for any new U.S. military action, with Trump explicitly mentioning Iran and Russia in connection with the weekend attack.
U.S. Defense Secretary Jim Mattis on Monday accused Russia of falling short of its obligation to ensure that Syria had abandoned its chemical weapon capabilities.
During the U.N. Security Council meeting on Monday, Russia and Syria both offered to take Organisation for the Prohibition of Chemical Weapons investigators to Douma.
The organization did not immediately respond to a request for comment. But after being attacked twice since 2013 while trying to get to the sites of chemical weapon attacks, weapons inspectors are not expected to go to Syria. Instead, they have in recent investigations gathered blood samples from victims and interviewed witnesses outside Syria.
The United States plans to call for a U.N. Security Council vote on Tuesday on a proposal for a new inquiry into responsibility for the use of chemical weapons in Syria, diplomats said.
