WASHINGTON, April 11, (RTRS): Senior White House officials accused Russia on Tuesday of trying to deflect blame from Syrian President Bashar al-Assad for a deadly poison gas attack on civilians last week that the United States has laid firmly at the feet of the Syrian government.The officials, who briefed reporters on condition of anonymity, said Assad’s government carried out the April 4 chemical weapons attack in Khan Sheikhoun as part of an effort to put pressure on Syrian rebels who were making advances in the area.Russia has defended the Syrian government, a staunch ally, against US allegations it was behind the sarin nerve gas attack in Syria’s Idlib province, saying there is no evidence to underpin such an allegation. It has blamed Syrian rebels.The officials said Russia has frequently spun out multiple, conflicting accounts in order to create confusion and sow doubt within the international community. “Russia’s allegations fit with a pattern of deflecting blame from the (Syrian) regime and attempting to undermine the credibility of its opponents,” one of the White House officials said.The United States launched 59 cruise missiles at a Syrian airfield last Thursday to retaliate against the chemical weapons attack, which killed 87 people, many of them children. US intelligence indicates that the chemical agent was delivered by Syrian Su-22 aircraft that took off from the Shayrat airfield, a White House report given to reporters said.The planes were in the vicinity of Khan Sheikhoun about 20 minutes before the attack began and vacated the area shortly afterward, the report said. “Additionally, our information indicates personnel historically associated with Syria’s chemical weapons program were at Shayrat airfield in late March making preparations for an upcoming attack in northern Syria, and they were present at the airfield on the day of the attack,” the report said.One of the White House officials said Assad used the attack as part of an “operational calculus” to slow rebel advances by attacking civilians. The officials had no comment on whether Russia might have colluded with Syria on the attack. The US intelligence community has no consensus on whether Russia knew about the attack in advance, the officials said.US Secretary of State Rex Tillerson carried a message from world powers to Moscow on Tuesday denouncing Russian support for Syria’s Bashar al-Assad, as the Trump administration took on America’s traditional mantle as leader of a unified West. Tillerson flew on the administration’s first cabinet mission to Russia after meeting foreign ministers from the Group of Seven advanced economies and Middle Eastern allies in Italy.They endorsed a joint call for Russia to abandon Assad. The administration of President Donald Trump, which came to power in January calling for warmer ties with Russia, was thrust into confrontation with Moscow last week when a poison gas attack in northern Syria killed 87 people. Western countries blame President Assad for the gas attack, and Trump responded by firing cruise missiles at a Syrian air base. Russian President Vladimir Putin has stood firmly by Moscow’s ally Assad, who denies blame. “It is clear to us the reign of the Assad family is coming to an end,” Tillerson told reporters in Italy before departing for Moscow. “We hope that the Russian government concludes that they have aligned themselves with an unreliable partner in Bashar Al-Assad.” He said Russia had failed in its role as sponsor of a 2013 deal under which Assad promised to give up his chemical arsenal. “These agreements stipulated Russia as the guarantor of a Syria free of chemical weapons,” Tillerson said. “It is unclear whether Russia failed to take this obligation seriously and whether Russia has been incompetent. But this distinction doesn’t much matter to the dead. We can’t let this happen again.”Russia says the chemicals that killed civilians belonged to rebels, not to Assad’s government, and has accused the United States of an illegal act of aggression against Syria on a phoney pretext. Putin said on Tuesday he believed Washington planned to launch more missile strikes, and that rebels were planning to stage chemical weapons attacks to provoke them.