Sweden must ask its banks to hold more capital on their balance sheets than the minimum required by regulation and should also prepare for cyber attacks, the country's central bank governor said in testimony to parliament on Tuesday.

"In this serious geopolitical situation, we need to strengthen the preparedness of the entire financial system, and it is of great importance to work to increase resilience to cyber attacks, among other things," Erik Thedeen said.

While the resilience in the financial system was continuously improving, this was not keeping up with the rapid pace at which threats were developing, the Riksbank chief added.

He said a mix of geopolitical turmoil, highly leveraged property companies and the high level of private debt in Sweden mean that the risks in the financial system are elevated, and that banks must take this into account.

"The Riksbank therefore considers that the major banks should for the time being aim to have a margin down to the formal capital requirements that is not less than the upper limit set by the banks themselves for their management buffers," Thedeen said. (Reporting by Anna Ringstrom, editing by Terje Solsvik and Essi Lehto)