US Secretary of State in Moscow

Travelling to Moscow on Tuesday, US Secretary of State Rex Tillerson became the first high-ranking official from the Trump administration to do so. The top diplomat and his Russian counterpart Sergey Lavrov were expected to discuss Syria and the deteriorating security situation in Libya.

Ahead of the visit, Tillerson said Russia must choose between aligning itself with the US and likeminded countries or embracing Syrian President Bashar Assad, Iran and the militant group Hezbollah.

The US secretary of state added that the US sees no future role for Assad in Syria, but that Washington isn't pre-supposing how Assad's departure will occur. Russia's foreign ministry, meanwhile, said it hoped for "productive talks."

Read: US-Russian honeymoon turns sour over Syria

As the former CEO of petroleum giant Exxon Mobil, Tillerson has a lot of business experience in Russia, but none as a government emissary. Coming amidst escalating tensions over a recent gas attack in Syria, the Secretary of State is likely to face his toughest diplomatic challenge yet.

"Rex Tillerson will probably tell the Russians that there are no further plans for military operations in Syria," security and foreign policy expert Thomas Wright of the Brookings Institution told DW. It is a difficult matter to predict, as the Trump administration has changed tack on Syria several times in recent weeks. 

Last week, after years of avoiding direct military strikes in Syria, the US launched an attack on a Syrian air base in response to a suspected chemical attack that killed at least 86 people and injured hundreds.

Moscow has supported Assad's claims that the tragedy was the result of Islamist rebels stockpiling the nerve agent sarin in a warehouse that was targeted in an airstrike.

G7 pushes tough talk to Moscow

Time will tell if US President Donald Trump is pivoting towards taking a tougher stance on Russia after numerous officials in his campaign and transition teams have been implicated in cases of legally dubious ties to Russian officials.

Thus far, the administration has insisted that it will "take additional action, as necessary and appropriate," if Assad continues to use illegal chemical weapons.

The Kremlin, for its part, called the US missile strike "a flagrant violation of international law and an act of aggression."

Tillerson's trip comes hot on the heels of his visit to Italy for a G7 summit, where Russia's role in Syria topped the agenda. According to German Foreign Minister Sigmar Gabriel, Washington is seeking "non-violent, non-military" solutions in Syria.

"We emphatically support him in his endeavors…in Moscow," said Gabriel of Tillerson. "I believe that it is almost inconceivable that Russia wants to stand on the side of such a murderous regime as that of Syrian President Bashar al-Assad for the long haul."

es,ksb/rt (AP, dpa)