By Steve Holland and Michelle Nichols
WASHINGTON/UNITED NATIONS (Reuters) - U.S. President Donald Trump on Monday promised quick, forceful action in response to a "barbaric" suspected chemical weapons attack in Syria, appearing to suggest a potential military response.
Speaking at a meeting with military leaders and national security advisers, Trump said he would make a decision by Monday night "or very shortly thereafter" on a response, adding that the United States had "a lot of options militarily" on Syria.
“But we can’t let atrocities like we all witnessed ... 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.”
The suspected chemical weapons attack late on Saturday killed at least 60 people, with more than 1,000 injured in several sites in Douma, a city near the capital, Damascus, according to a Syrian aid organization.
Two days later, the White House was still only able to say that the attack fit the pattern of Syrian President Bashar al-Assad's chemical weapon use.
Initial U.S. assessments have so far been unable to determine conclusively what materials were used in the attack and could not say with 100 percent certainty that Assad's government forces were behind it.
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."
On Sunday, the U.S. president who had sought warmer relations with Russia criticized Putin by name on Twitter as he castigated Russia and Iran for backing "Animal Assad."
The U.S. envoy to the United Nations, Nikki Haley, said Washington "will respond" to the attack regardless of whether the U.N. Security Council acts or not.
The Syrian government and its ally Russia have denied involvement in the attack.
International bodies led by the Organisation for the Prohibition of Chemical Weapons (OPCW) were trying to establish exactly what happened in Douma, a rebel-held town in the eastern Ghouta district.
'SHOCKED THE CONSCIENCE'
Britain and the United States agreed on Monday that the attack bore the hallmarks of previous chemical weapons attacks by Assad's government but neither country gave details of what kind of chemical might have been used or how the attack was staged.
"The images, especially of suffering children, have shocked the conscience of the entire civilized world," White House spokesman Sarah Sanders said. "Sadly, these actions are consistent with Assad's established pattern of chemical weapons use."
The United States 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 on its obligations to ensure that Syria abandoned its chemical weapons capabilities.
Russia and Syria both offered during the U.N. Security Council meeting on Monday to take OPCW investigators to Douma.
The OPCW did not immediately respond to a request for comment. But weapons inspectors are not expected to go to Syria after being attacked twice while tying to get to the sites of chemical weapons attacks since 2013.
Instead, they have in recent investigations gathered blood samples from victims and interviewed witnesses outside of Syria.
"As we've said, Russia has time and again shown that it is unable or unwilling to stop these kind of attacks. I put little credibility in these type of statements or offers from Russia at this point," a U.S. official told Reuters.
MONDAY AIR STRIKES
The Syria conflict was further complicated on Monday when unidentified war planes struck a Syrian air base near Homs, killing at least 14 people, including Iranian personnel. Syria and Russia accused Israel of carrying out the attack.
Israel, which has struck Syrian army locations many times in the course of its neighbor's 7-year-old civil war, has neither confirmed nor denied mounting the raid.
But Israeli officials said the Tiyas, or T-4, air base was being used by troops from Iran and that Israel would not accept such a presence in Syria by its arch foe.
Russian Foreign Minister Sergei Lavrov said the strike on the T-4 base was a dangerous development.
The incidents in Douma and Tiyas demonstrated the complex and volatile nature of the Syria war, which involves a number of countries and a myriad of insurgent groups.
Assad now has the upper hand in the conflict, but any international action could delay his efforts to bring it to a close.
The U.S. State Department said on Monday that the Douma victims' symptoms were consistent with those caused by a nerve agent but they could not confirm what had been used.
It urged Russia and the Syrian government to allow international monitors access to the affected areas.
The Russian military said on Monday its medics had examined patients in a hospital in Douma and had found no traces of a chemical attack, Interfax news agency reported.
Syrian government forces had launched an air and ground assault on Douma, the last town held by rebels in eastern Ghouta, on Friday.
The Union of Medical Care Organizations (UOSSM) said at least 60 people had been killed by the alleged chemical attack.
"The numbers keep rising as relief workers struggle to gain access to the subterranean areas where gas has entered and hundreds of families had sought refuge," it said.
One video shared by activists showed bodies of about a dozen children, women and men, some with foam at the mouth. Reuters could not independently verify the reports.
The OPCW, based in The Hague, opened an investigation on Monday to determine whether dozens of people were gassed to death in the attack.
U.N. war crimes investigators had previously documented 33 chemical attacks in Syria, attributing 27 to the Assad government, which has repeatedly denied using the weapons.
(Reporting by Steve Holland and Michelle Nichols; Additional reporting by Nayera Abdallah, Suleiman Al-Khalidi, Ellen Francis, Maria Kiselyova, Dan Williams, John Irish, Anthony Deutsch, Lesley Wroughton, Matt Spetalnick; Writing by Doina Chiacu, Yara Bayoumy and Angus MacSwan; Editing by Alistair Bell and Peter Cooney)