Tillerson is in for a tricky trip to Moscow

REX Tillerson visits Moscow for his first meetings as US Secretary of State with Russian President Vladimir Putin on Tuesday and Wednesday. The spike in Washington-Moscow tensions over Syria will dominate their discussion, and both sides are looking for ways to de-escalate a situation which Russian Prime Minister Dmitry Medvedev said last week has put them "one step away from war" and "totally ruined" relations.

Signs of rising tensions include Moscow's suspension of an agreement with Washington to share communications about US and Russian aircraft conducting missions over Syria; the Admiral Grigorovich frigate warship has been sent from Crimea to the Syrian port of Tartus.

In the unexpected turn of events last week, US missile strikes targeted the Shayrat air base following an earlier poison gas attack on citizens in a rebel-held town allegedly committed by the Damascus regime; at least 80 people, including around two dozen children, died.