After the U.S. airstrike on the Syrian air base that was used to launch the Khan Shaykhun chemical attack, pressure on the White House to take more concrete steps toward a solution in Syria has increased while political rhetoric aimed at influencing Russia to lessen its support for the Assad regime has also increased.

President Recep Tayyip Erdoğan asked Russia to reconsider its support on the Syrian regime on Saturday after a chemical weapons attack in Idlib last week killed at least 100 men, women, and children and injured more than 500.

It was the most horrific chemical weapons attack in the war-torn country since a similar attack in eastern Damascus in August 2013, the World Health Organization (WHO) said. The Ghouta attack left more than 1,300 civilians dead, mostly women and children, according to local and international human rights groups."It is our hope that this will not be limited to U.S. action," Erdoğan said while speaking about responding to the Khan Shaykhun attack as well as the broader Syrian conflict, in a live broadcast on Turkey's Kanal 24."We hope that Russia gets involved as well - that [the Kremlin], at the very least, will stop defending Assad," Erdoğan said, while also welcoming Moscow's recent statement that "unconditional support [of the Syrian regime] is not possible.""But, let's speed it up," the president said, adding: "Let's get rid of this evil." The president emphasized the need to reinvigorate the pursuit for a political solution. "If we say democracy, let's take this step," he said.'White House vows to take further steps in Syria'Meanwhile, the Trump administration has changed its position regarding the removal of Assad, saying a political solution to the Syrian crisis is not possible while Bashar Assad is in power. The U.S.'s envoy to the U.N. Nikki Haley underlined the new position of the U.S. on Saturday, saying: "There's not any sort of option where a political solution is going to happen with Assad at the head of the regime," during an interview with CNN. "It just – if you look at his actions, if you look at the situation, it's going to be hard to see a government that's peaceful and stable with Assad," said Haley, purporting a very different stance from the U.S.'s position regarding Assad just a week prior to the chemical attack.In addition, the White House has vowed to keep up the pressure on Syria, despite the prospect of escalating tensions with rival superpower Russia.In a letter to Congress on Saturday, Trump said he "acted in the vital national security and foreign policy interests of the U.S., pursuant to my constitutional authority to conduct foreign relations" as commander in chief and chief executive.He said the U.S. "will take additional action, as necessary and appropriate, to further its important national interests."A key test of whether the U.S.-Russia relationship can be salvaged comes next week when Secretary of State Rex Tillerson becomes the first Trump Cabinet member to visit Russia. Russian Foreign Minister Sergey Lavrov and U.S. Secretary of State Rex Tillerson have discussed the U.S. missile strike on Syria's Shayrat air base in a phone call, the ministry said Saturday. The two leaders have reportedly agreed to continue discussing the situation in Syria next week during a face-to-face meeting as part of Tillerson's two-day visit to Moscow April 11-12.At the U.N. on Friday, Russia's deputy Ambassador Vladimir Safronkov strongly criticized what he called the U.S.'s "flagrant violation of international law and an act of aggression" whose "consequences for regional and international security could be extremely serious."Foreign Minister Mevlüt Çavuşoğlu said the U.S. missile strikes were not enough. Çavuşoğlu said Saturday that the U.S. intervention is only "cosmetic" unless it results in the removal of Assad from power. He said the most ideal process would be a political solution that leads to a transitional government.Thursday night's strikes, which included the launching of some 60 cruise missiles fired from two ships in the Mediterranean, were the culmination of a rapid, three-day transformation for Trump, who has long opposed deeper U.S. involvement in Syria's civil war. Advisers to the president said he was outraged by heartbreaking images of young children who were among the dozens killed in the chemical attack.'No doubt Assad has chemical weapons'Meanwhile, President Erdoğan said Syria "undoubtedly" has chemical weapons and it is clearly known whose airplanes dropped the bombs on civilians "as we have radar records."The president also mentioned Turkish government statements saying that the use of a nerve agent was detected during the treatment of chemical weapons attack victims on the Turkey-Syria border in the presence of World Health Organization (WHO) experts.He stressed that whether the attack is chemical or not, nearly 1 million victims have been killed in Syria, and the world should take action against all kind of civilian casualties, regardless of how the victims were killed. Erdoğan said while there was good progress in the Astana talks – carried out in parallel to the Geneva process – to reach a political agreement in Syria, "unfortunately [the talks] did not develop as we wanted."