He will say that Assad has no future in Syria, Russia must stop supporting the regime and a plan to rebuild the country must be drawn up.
Putin said Russian Federation and Syria were being portrayed as a "common enemy" in a bid to bring together the USA and its Western allies after many leaders criticised Trump ahead of his election.
Pressed to clarify, McMaster said the goals of fighting IS and ousting Syria's president were somewhat "simultaneous" and that the objective of the missile strike was to send a "strong political message to Assad".
Until Trump ordered USA missile strikes in response to the nerve gas attack that killed more than 80, the president had focused on defeating the Islamic State group and had shown no appetite for challenging Assad - and, by extension, his Russian supporter President Vladimir Putin. USA warships fired 59 cruise missiles at the Syrian air base from which the US believes the attack was launched. But they were divided about how to deal with Syria, and Moscow.
During his first day in Italy, Tillerson plans to meet Monday with foreign ministers from the United Kingdom and France before the G-7 summit formally opens.
Russia's foreign ministry said that it hoped for "productive talks", and that the outcome of discussions was important "for the overall atmosphere on the world stage".
But Alfano said isolating Russian Federation or pushing it into a corner "would be wrong".
Instead of sanctions, the meeting's final communique called for an investigation by the Organization for the Prohibition of Chemical Weapons to determine who was responsible for the "war crime".
Britain is keen for the ministers' meeting to produce a tough statement and perhaps a threat of new sanctions if Moscow does not end its military support for Assad. There are already believed to be at least 900 US troops in Syria fighting ISIS, which includes the addition of around 400 troops added last month.
But others want a more conciliatory approach.
Tillerson also spoke by phone with Turkish Foreign Minister Mevlut Cavusoglu, whose government insists Assad should play no role in Syria's future.
In a letter to Trump, two Republican lawmakers Senator Marco Rubio and Congressman Peter Roskam urged him to suspend aircraft sales to Iran arguing that Tehran is using commercial passenger aircraft to supply its worldwide network of terror proxies, including the Assad regime in Syria. The G-7, or Group of Seven, is comprised of the world's seven major advanced economies, including: the U.S., U.K., Canada, France, Germany, Italy and Japan.
As his administration used US intelligence to pressure Moscow over its support for Syrian President Bashar Assad, Russian President Vladimir Putin parroted back Trump's doubts about the reliability of USA spy agencies.
Sen. John McCain, R-Arizona, said comments made by people in President Donald Trump's administration are "partially to blame" for encouraging Syrian President Bashar al-Assad's apparent use of chemical weapons on his people last week.
In his opening remarks, Tillerson said he was looking forward to "an open, candid, frank exchange" with Lavrov.