Schools cannot reopen, the Presidential Task Force (PTF) on COVID-19 said on Thursday.
The government cited the need to protect the vulnerable and halt the spread of the virus in communities as reasons.
Mustapha said this during the daily briefing by the PTF in Abuja.
PTF chair Boss Mustapha said: “Nigeria witnessed a spike in number of confirmed cases when the number of recorded cases jumped to 663 on June 9. This number gives us cause for concern as a Task Force and as a nation.
“The PTF will re-emphasize its appeal to governments at the sub-national level as well as our security agencies to enforce the guidelines and protocols firmly.
“The PTF would also be meeting with the heads of these agencies to further fine-tune strategies to ensure compliance.
“We must ensure that our goal is to stay alive and remain COVID-19 free,” he added.
Mustapha described school resumption as delicate since Nigeria had entered the phase of community spread of the virus.
He said Nigeria should pursue a strategy that will aid the sustainable control of the spread of the disease, adding that communications and community engagement should remain top priority, while precision approach to containment and management should be adopted.
He said the PTF had put in place measures to fight against COVID-19, including the application of science and data to guide the targeting of areas of on-going high transmission, mobilisation of all resources at State and Local Government levels to create public awareness on COVID 19 and improve compliance with non-pharmaceutical interventions within communities and sustenance of key non-pharmaceutical interventions that would apply nationwide and include among others.