Global financial stability could come under pressure if some of the harshest possible sanctions are imposed on Russia over its aggression towards Ukraine, the chair of the world’s most powerful financial regulator warned.

Western allies have been discussing a raft of measures to punish Russia in the event of an attack on Ukraine. While it is not thought to be the most likely option initially, severing Russian banks’ ties to international payments network Swift is reportedly among the harshest measures under consideration.