US Secretary of State Rex Tillerson has said that Russia needs to choose whether to continue their alignment with Syrian dictator Bashar al-Assad, Hezbollah and Iran or realign themselves with America and its allies.

In advance of his trip to Moscow this week – where difficult questions about Russia's knowledge and involvement in a chemical attack on Syria will almost certainly be on the table – Tillerson told reporters at the G7 summit in Lucca, Italy on 11 April that Russia had "aligned themselves with an unreliable partner in Bashar al-Assad".

"Russia has really aligned itself with the Assad regime, the Iranians, and Hezbollah. Is that a long-term alliance that serves Russia's interest, or would Russia prefer to realign with the United States, with other Western countries and Middle East countries who are seeking to resolve the Syrian crisis?" Tillerson asked.

"We want to relieve the suffering of the Syrian people. We want to create a future for Syria that is stable and secure," the Secretary of State continued, "and so Russia can be a part of that future and play an important role, or Russia can maintain its alliance with this group, which we believe is not going to serve Russia's interest longer-term.

"But only Russia can answer that question."

Tllerson made the comment at the G7 meeting where he called for the "direct participation" of other G7 countries in stablising Syria. Tillerson and UK Foreign Secretary Boris Johnson were reportedly finalising places to increase sanctions on Russia if the country did not back away from Assad after the chemical attack – but that call was shot down by other G7 members.

Tillerson arrived in Moscow hours after making the statement, where he is due to meet Russian Foreign Minister Sergey Lavrov during his two-day visit.

When asked if a meeting between Tillerson and President Vladimir Putin was deliberately being avoided amid the backdrop of recent US missile strikes on Syria, Kremlin spokesman Dmitry Peskov said: "I don't understand what you mean. Go on discussing it."