In a gloomy Quarterly Inflation Report, King blamed the current crisis on the further tightening of credit conditions and a collapse of consumer confidence.
"Restoring both lending and confidence will not be easy and will take time," he added.
The governor hinted at the possible commencement of "quantitative easing", sometimes erroneously termed printing money, where the BoE would buy up assets in order to increase the availability of corporate credit.
King said that the BoE would open its facility to make such purchases this week but warned that it would take a long time for this to have a "noticeable impact" on activity.
It is also likely that the UK will experience a period of deflation with the inflation rate falling to "well below" the 2%, despite the low interest rates, he said.
However, experts predict that, should quantitative easing be successfully implemented, a period of high inflation will follow.
Bank of England governor says UK in 'deep recession'
The UK economy is in a "deep recession" and its length depends on international developments, the Bank of England (BoE) governor Mervyn King has warned.
