OTTAWA – Prime Minister Justin Trudeau is taking part in a secret intelligence briefing today with the leaders of the United Kingdom, Australia and New Zealand — a high-level meeting where Russia and Syria are expected to be on the agenda.

Trudeau and his three counterparts, whose countries together with the U.S. are part of the tightly knit Five Eyes intelligence alliance, have gathered in London for this week’s summit of Commonwealth leaders.

Today’s meeting follows a troubling warning this week from the U.S. and the U.K. that said Russia is involved in an unprecedented level of cyber-infiltration and attacks, including targeting the household routers many people use at home.

Canadian officials have not commented on the warning.

Trudeau met with British Prime Minister Theresa May in the gardens of 10 Downing Street in advance of the security briefing, where the two identified trade as well as Syria and Russia as topics of conversation.

Britain has been locked in a bitter standoff with Russia since a former Russian spy and his daughter were poisoned in the city of Salisbury last month, an attack the U.K. and its allies, including Canada, have blamed on Moscow.