The Southern African Development Community (SADC) security summit that was to be held in Mozambique on Thursday has been postponed.
Mozambican Foreign Minister Veronica Macamo said the body did not have a quorum because Botswana's and South Africa's presidents would be absent.
Botswana's Mokgweetsi Masis is self-isolating after his staff members contracted Covid-19 while South Africa's Cyril Ramaphosa is testifying in a corruption inquiry.
The Botswana government had in a statement said that the vice-president would represent the president.
Minister Macamo said that SADC had agreed to intervene on the insecurity in Cabo Delgado province and that it was the heads of states who would come up with lasting solutions.
The province has had a series of attacks by Islamist militants.