Kuleba said recent Russian strikes on the Ukrainian port of Reni, on the border with NATO member Romania are a way for Russian President Vladimir Putin to "test the reaction of NATO". "NATO has to react firmly and decisively in response to this," he said.
He confirmed that "Russian ships, wherever they are in the Black Sea, become legitimate targets" in response to Moscow's own warning that civilian ships heading to Ukrainian ports would now be targets.
The top Ukrainian diplomat vowed that Kyiv would "keep trying" to revive the Black Sea Grain Initiative following Russia's withdrawal.
He added, however, that if this is not feasible, an alternative sea route to export Ukrainian grain needs to be put in place, as well as ensuring exports to Europe.