British foreign minister David Lammy described the supply of ballistic missiles from Iran to Russia on Tuesday as a "significant escalation."
"This is a troubling action that we're seeing from Iran. It is definitely a significant escalation and we are coordinating," he told a press conference alongside U.S. Secretary of State Antony Blinken.
Lammy said he would not comment on "operational issues" when asked whether Britain would give the green light to Ukraine to use the Storm Shadow long-range missiles to strike targets inside Russia.