The Queen Elizabeth Hospital in Norfolk has promised to take swift action to improve its quality of care after being placed in special measures.
Following confirmation from the Care Quality Commission that the health regulator Monitor was to intervene, the King's Lynn trust apologised to patients.
Acting chief executive at the QEH, Sharon Beamish, said: "We accept the reports' findings and as a board we will work with Monitor to do everything we can to put things right as quickly as possible."
The hospital said it was taking immediate action to ensure wards were adequately staffed.
A further 35 nurses from Portugal are due to start work at the King's Lynn site in November and December and the trust is continuing to recruit from across the UK - including newly-qualified staff from the University of East Anglia and Anglia Ruskin University.