There have been 273 more Covid-19 cases recorded in Northern Ireland in the past 24 hours, the Department of Health has said.
It is the highest daily number of cases since the pandemic began.
There were no further deaths recorded, meaning the total number remains at 577.
Since the pandemic began, 10,223 people have now been confirmed as having contracted Covid-19.
In hospitals around the north, 44 patients have tested positive for coronavirus. Five patients have been ventilated in intensive care.
There are 27 confirmed outbreaks in care homes and 12 suspected outbreaks.
Health Minister Robin Swann told the Assembly in an urgent written statement there has been a "marked increase" in cases as well as a "progressive rise in Covid hospital patients".
"The Executive continues to prioritise public health, while also recognising the importance of keeping society and the economy as open as possible," he said.
"As health minister, I recognise the consequences for population health and wellbeing of economic stagnation."
Mr Swann has not ruled out introducing further measures to try to stem the increase in cases of the virus.
"As we look ahead, we have to plan for every eventuality," he said.
"There is early evidence to suggest that the household restrictions applied on a postcode basis, and now Northern Ireland wide, may have had some impact on reducing transmission.
"My department and the Executive will continue to monitor the data on prevalence and be guided by expert medical and scientific advice.
"I am advised that further interventions may be required to prevent an exponential rise in the virus.
"In the coming days and weeks, the Executive will continue to assess different potential options for returning incidence to low levels."
Earlier the chief medical officers from Northern Ireland and the Republic of Ireland made a joint statement to advise against all but necessary travel across the border.
There has been an increase in case numbers in Co Donegal with tighter coronavirus restrictions decided by the Irish Government to be imposed at midnight to remain in place until October 16.
"Given the current number of new cases in Donegal and neighbouring areas we would appeal to everyone to avoid all but necessary travel across the border," Dr Michael McBride and Dr Ronan Glynn said.
"It is also recommended that employers on both sides of the border make every effort to facilitate employees to work from home in so far as is possible."
Earlier today, the Northern Ireland Statistics and Research Agency (Nisra) said that up until September 18, 891 deaths involving the virus were registered.
Nisra records all cases where Covid is mentioned on the death certificate whereas the Department of Health only includes those who died following a positive test.
This afternoon Taoiseach Micheál Martin urged leaders in the north to harmonise public health measures as the number of Covid-19 cases grows rapidly on both sides of the border.
The Fianna Fáil leader spoke to First Minister Arlene Foster and Deputy First Minister Michelle O'Neill after the Dublin government said it is tightening coronavirus restrictions in Co Donegal.
Meanwhile, an additional 326 cases of Covid-19 have been confirmed in the Republic of Ireland, the National Public Health Emergency Team (Nphet) said.
No further deaths due to the virus were reported.
Acting chief medical officer Dr Ronan Glynn said: "Today I am asking people everywhere, but particularly in Donegal and Dublin, to pay special attention to the public health advice.
"I ask every individual to take personal responsibility to prioritise who you need to see, limit the size of your social network and reduce your social contacts over the coming days and weeks.
"Because while there is every chance that other areas will have to move to level 3, there is nothing inevitable about it.
"We have seen previously how people working together can turn the tide on this virus and bring increasing trajectories back under control."
