Nyusi flew over areas that were otherwise accessible, and some of which had been hit by flooding before Cyclone Idai.
At least 89 people have died in Zimbabwe after Cyclone Idai tore across the eastern and southern parts of the country, a government official said on Monday, creating a humanitarian crisis in a nation grappling with economic woes and a drought.
In Zimbabwe, early estimates from government sources in Chimanimani District in Manicaland, put the numbers affected by the cyclone as approximately 1,600 households (8,000 people), with 23 deaths and 71 people reported missing.
"I think this is the biggest natural disaster Mozambique has ever faced".
On March 15, the International Federation of Red Cross and Red Crescent Societies tweeted that people "are now facing a second threat of flash floods" after the cyclone hit Malawi.
This handout picture taken and released on March 18, 2019 shows damages in Beira, Mozambique, in the aftermath of the passage of the cyclone Idai.
Zimbabwe Association of Doctors for Human Rights executive director Calvin Fambirai said with the emerging health and medical challenges, they would be deploying doctors to the affected communities.
The majority of those unaccounted for are thought to be government workers, whose housing complex was completely engulfed by raging waters. Their fate was unknown because the area was still unreachable.
Liverpool winger Sadio Mane doubtful for Fulham game?
Ajax last won the Champions League in 1995, while Manchester United last won in 2008 and Juventus most recently won in 1996. The Sky Blues are favourites to win all three competitions, thus winning a historic quadruple.
"We are here because our house has been submerged by the water", the 35-year-old said. "It's very sad and the situation is dire".
Among the dead are at least two school children who perished when a rock fell from a nearby mountain, trapping dozens of students in a dormitory in Zimbabwe.
Almost 200 pupils and their teachers at St Charles Luwanga School in Chipinge, who had been stranded since Friday, were rescued Sunday.
Sisulu also appealed to South African NGOs, companies and individuals to make donations towards humanitarian aid for the people of Malawi, Zimbabwe and Mozambique affected by Tropical Cyclone Idai.
Roads and bridges have been severely damaged while thousands of people have been left homeless after their homes collapsed in the driving rains and floods.
"Some runway lights were damaged, the navigation system is damaged, the control tower antennas and the control tower itself are all damaged", an official at the National Institute of Disaster Management (NIDM) told AFP on Friday.
The airport was set to reopen on Sunday as flights began taking off from the capital Maputo bound for Beira.