Story highlights US, Russia relations deteriorate following missile strike on Syria

Tillerson due to meet Lavrov in Moscow this week

(CNN) The United States will "hold to account" any government that commits atrocities against innocent people, Secretary of State Rex Tillerson said Monday, as key US allies met to work out a common stance on Syria.

Tillerson spoke at an Italian war memorial before a meeting of foreign ministers from the G7 industrialized nations, which was dominated by the diplomatic fallout from the unexpected US missile strike on a Syrian airbase last week.

"We rededicate ourselves to holding to account any and all who commit crimes against the innocents anywhere in the world," Tillerson said in a short statement commemorating a 1944 German Nazi massacre in Sant'Anna di Stazzema.

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Tillerson went on to meet his G7 counterparts at a summit in the nearby Tuscan city of Lucca -- the first meeting of US allies since President Donald Trump ordered the bombardment on the Shayrat airbase in western Syria last week.

Diplomats were attempting to agree a common line before Tillerson meets Russian Foreign Minister Sergey Lavrov in Moscow later this week. British Foreign Secretary Boris Johnson told the BBC that the priority for the G7 summit was to give a "clear mandate" to Tillerson as he headed to Moscow.

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