Mounting pressure on Assad-friendly Russia,

LUCCA, ITALY— Foreign ministers from the Group of Seven industrialized nations met Monday to forge a response to the deadly chemical attack in Syria, with U.K. Foreign Secretary Boris Johnson saying they would consider imposing sanctions against Russian backers of President Bashar Assad.

G7 diplomats, including Canadian Foreign Minister Chrystia Freeland hope to use outrage over the attack and wide international support for the United States’ retaliatory missile strikes to push Russia to abandon Assad and join a new peace effort for Syria. Speaking after meeting with U.S. Secretary of State Rex Tillerson, Johnson said ministers “will be discussing the possibility of further sanctions, certainly, on some of the Syrian military figures and indeed on some of the Russian military figures.”

He said Russia had a choice: to continue backing the “toxic” Assad regime, “or to work with the rest of the world to find a solution for Syria, a political solution.”

Last week’s nerve gas attack in the rebel-held town of Khan Sheikhoun, which killed more than 80 people, stirred U.S. President Donald Trump — who was previously cool to the idea of U.S. intervention — to strike for the first time at Assad’s forces.

Tillerson said Monday at the site of a Second World War-era Nazi massacre in central Italy that the U.S. is rededicating itself to hold to account “any and all” who commit crimes against innocent people.

Tillerson is due to travel to Russia after the G7 gathering, and Johnson said he will deliver a “clear and coordinated message to the Russians.”