Cyclone Idai lashed the Mozambican port city of Beira with winds of up to 170 km per hour (105 miles per hour) last week, then moved inland to Zimbabwe and Malawi, flattening buildings and putting the lives of millions at risk.
"The situation is getting better, still critical, but it's getting better," Land and Environment Minister Celso Correia said, adding that it was becoming easier to work on the ground.
"But unfortunately the number of dead is increasing, we have now 417 people who have lost their lives," he said.
The floods have left thousands of people scrambling for shelter, food and water.
Some survivors have taken refuge at churches and centers offering temporary shelter, while individuals joined international aid agencies and the government in rushing humanitarian aid to affected areas.
Correia said 1,500 people were in need of immediate rescue from rooftops and trees.
The storm's rains caused the Buzi and Pungwe rivers to burst their banks, and the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said there was "always the risk of more flooding."
"We're going to have to wait until the flood waters recede until we know the full expanse of the toll on the people of Mozambique," OCHA coordinator Sebastian Rhodes Stampa said.
He added that the Buzi and Zambezi could break their banks again as heavy rains inland poured into low-lying Beira and surrounding areas.
Dams around the port city of 500,000 people were also filling up, and threatening to overflow or break. The release of water from dams upstream in Zimbabwe was also a concern.
"The main challenge at the moment is the weather," Rhodes Stampa said.
The storm has killed 259 in Zimbabwe, and the number was expected to rise, relief agencies said. In Malawi, 56 people died in heavy rains before the onset of Cyclone Idai.
The International Federation of the Red Cross and Red Crescent Societies (IFRC) said on Friday that cases of cholera have been reported in Beira.
Both Correia and Rhodes Stampa said that cholera and other water-borne diseases were not yet a problem, though floodwaters were dirty and the risk of disease spreading was high.
Rhodes Stampa said there were not any confirmed cases yet, but added: "It doesn't mean we won't."