Trump warns poison gas attack in Syria goes ‘beyond red lines’

President Donald Trump said an apparent poison gas attack in Syria that killed more than 70 people has changed his thinking on the six-year crisis, as the U.S. signaled a more aggressive response to a conflict that Western leaders and the UN have struggled to resolve.

Asked Wednesday if the gas attack crossed a 'red line,” Trump said it 'crossed a lot of lines for me. That crosses many, many lines, beyond red lines.”

Standing alongside King Abdullah II of Jordan at the White House, he called the incident 'an affront to humanity. These heinous actions by the Assad regime cannot be tolerated.”

The attack Tuesday, which two human rights and medical groups say bears the signs of illegal chemical weapons use, puts the Trump administration in a bind. If chemicals were used by Assad's military, it would mean Syria violated a deal to destroy such weapons, an accord brokered by the Obama administration and Russia after an August 2013 sarin gas attack killed more than 1,000 people in a Damascus suburb.

As a private citizen at the time, Trump slammed proponents of greater involvement in Syria following that attack, saying the U.S. should 'stay away” from the crisis.

'What will we get for bombing Syria besides more debt and a possible long term conflict,” Trump said on Twitter Aug. 29, 2013. Five days later he wrote, 'What I am saying is stay out of Syria.”

On Wednesday, Trump said the latest attack had changed his views.

'It is now my responsibility,” to respond to the crisis, he said. 'My attitude toward Syria and Assad has changed very much.”

At the U.N. Security Council an hour earlier, U.S. Ambassador Nikki Haley, facing her most serious international crisis since becoming Trump's envoy in January, stood up at her desk to show diplomats photos of dying children gasping for air. She then accused Russia, which backs Syrian President Bashar Assad's regime, of pushing a 'false narrative” that blames rebel forces for the attack before issuing a new warning.

'When the United Nations consistently fails in its duty to act collectively, there are times in the life of states that we are compelled to take our own actions,” Haley said. A draft resolution under debate calls on Syria to provide UN investigators information about air operations, including the names of commanders of helicopter squadrons, on April 4. It also demands U.N. access to Syrian air bases.

While Trump slammed then-President Barack Obama for considering military engagement in Syria, the rising threat of Islamic State terrorism, which Trump has said is his top priority, has prompted him to boost the number of U.S. special forces in the Middle Eastern country. But it isn't clear how much further the administration would be willing to go, given that the Syrian regime is defended by Russian military forces, who first intervened to turn the war in Assad's favor in late 2015.

And while Assad was bolstered by Russia, the battle includes not just Syrian, Russian and Islamic State forces, but Kurdish, Turkish, Iranian and Hezbollah troops, the latter of which are also backed by Tehran. A U.S.-led coalition backs some rebel groups, while others have had alternating affiliations with Islamic State and al-Qaida.

Although Obama said 'Assad must go” in 2011, the U.S. and an alliance of rebels it backed never mounted a successful campaign to overthrow him. Statements by Trump and Secretary of State Rex Tillerson in the days before Tuesday's attack suggested the administration was resigned to seeing Assad remain in power. Yet the severity of Tuesday's assault fueled renewed calls from Western officials for Assad to step down following six years of civil conflict which has killed an estimated 400,000 people and sent millions more fleeing.

'If proven that the regime was behind this, it demonstrates once again the barbarity of Assad and the requirement that he must go,” U.K. Ambassador to the U.N. Matthew Rycroft told reporters outside the Security Council. 'He cannot be the person who unifies Syria after this war.”

Russia, which has vetoed seven previous Security Council resolutions critical of Syria, said the current resolution was 'categorically unacceptable.” Moscow has blamed the deaths in Tuesday's attack on rebels, saying in a Defense Ministry statement that the Syrian air force hit an ammunition depot in northern Idlib province where chemical weapons were stored.

Despite Russia's criticism of Wednesday's draft resolution, other UN diplomats said they still hoped for a vote as early as Wednesday afternoon.

In the wake of Tuesday's attack, the U.K.-based Syrian Observatory for Human Rights said its on-the-ground sources reported that one neighborhood 'was bombed with material believed to be gases which caused suffocation and other symptoms.”

The group Medecins Sans Frontieres, also known as Doctors Without Borders, said the attack victims showed symptoms consistent with exposure to at least two different chemical substances, including sarin gas and chlorine.

'I'm appalled by the reports that there's been a chemical weapons attack on a town south of Idlib allegedly by the Syrian regime,” U.K. Prime Minister Theresa May said while on a trip to Saudi Arabia. 'We cannot allow this suffering to continue.”

United Nations Secretary General Antonio Guterres was 'deeply disturbed” at the incident, even though the world body was not in a position 'to independently verify reports” of the chemical attack, according to UN spokesman Stephane Dujarric. If confirmed, the attack 'constitutes a serious violation of international law.”