"People should continue to use the NHS wisely and remember that they can seek help and advice from a range of other sources, such as pharmacies and NHS 111".
In total 47 NHS organisations reported being affected - and the disruption is continuing into the new working week.
Patients were being turned away from the Royal London Hospital yesterday amid delays in treatment and medication because staff had been warned not to use the computers.
"It is important to note that the vast majority of NHS organizations report that they are running contemporary IT systems, which are commissioned depending on local need", the NHS said in a statement.
Health board chief executive Ralph Roberts on Monday offered a public assurance that there has been "no direct impact on our IT systems".
"But our immediate priority as a government is to disrupt the attack, restore affected services as soon as possible, and establish who was behind it so we can bring them to justice". We are being careful and taking precautions to prevent anything being spread.
"We back up what we put into the system every night, but Friday's information will be gone".
It could be a "long time" before health services in Lancashire are running as normal after an global cyber attack.
Mr Palmer said that Jersey would not get a "free pass" and a "rapid response" of downloading patches was needed to defend against further waves of the cyber-attack. He said the situation was under control.
"The National Cyber Security Centre and the NCA are working with Europol and other worldwide partners to make sure that we all collect the right evidence, which we need to do, to make sure we have the right material to find out who has done this and go after them, which we will", she said.
Operations and appointments were cancelled and ambulances diverted as up to 61 NHS organisations, including many hospitals, became infected by the ransomware.
A spokesperson for Plymouth Hospitals NHS Trust, which runs Derriford, said: "Following Friday's cyber attack, patient care is going ahead as planned and patients are asked to attend the hospital for their appointments as normal at Derriford Hospital".
NHS Digital has confirmed to Sky News that the patch was made available on its cyber portal on 25 April, and a link sent to NHS IT staff on 27 April.
A spokesman said: "Our understanding is that if that had been acted on it would have prevented [the malware attack]".
"This means there has been no loss of personal data, nor are there any changes to planned clinical services", he said.
"IT Teams have been working all weekend however Computer systems will remain suspended tomorrow as a precaution whilst cyber-attack issues at our sister sites are dealt with".