"President Nkurunziza will not go to Dar es Salaam," Gervais Abahiro told AFP. "He will be represented there by his foreign minister. He is campaigning (for elections) and decided to delegate his minister."
The heads of state of Rwanda, Uganda, Tanzania and Kenya were to meet in the Tanzanian port city to tackle the crisis in Burundi stemming from Nkurunziza's controversial bid to stand for a third term in office.
It was during a first crisis meeting on May 13 in Tanzania's economic capital, attended by Nkurunziza, that a top general launched an unsuccessful bid to oust him.
Burundi's government insisted Friday that parliamentary elections will go ahead on June 5 despite the ongoing political crisis.
A presidential poll is scheduled for June 26.