US regulators added three foreign-owned banks to the list of big financial firms that have not shown they can collapse without causing broader economic damage.

The Federal Reserve and the Federal Deposit Insurance Corp found shortcomings in the "living wills," or bankruptcy plans, of the US units of BNP Paribas, HSBC and Royal Bank of Scotland. The banks could face sanctions if they do not fix the issues by the end of this year, when new drafts of the plans are due, the regulators said.