The informal gathering yesterday had been requested by Ukraine, whose UN representative was in attendance.
The meeting -- the panel's fifth on the issue in 10 days -- aims to give Ukraine "an opportunity to express its concerns about the developments and in particular about the prospect about the illegal referendum" set for Sunday, said British envoy Mark Lyall Grant.
The pro-Russian parliament on the Crimean peninsula has convened a referendum to decide whether to break away from Ukraine and join Russia. The vote is regarded as illegal by both Kiev and the West.
"That will be the message: 'no referendum, you have to respect the Ukrainian constitution and negotiate'" between Moscow and Kiev, he said.
The Security Council has so far failed to adopt a common position on the crisis. Moscow, a permanent member, can use its veto to block any decision by the body.