Some 143 people died in the flooding in Germany's worst natural disaster in more than half a century. That included about 98 in the Ahrweiler district south of Cologne, according to police.
Hundreds of people were still missing or unreachable as several areas were inaccessible due to high water levels while communication in some places was still down.
Residents and business owners struggled to pick up the pieces in battered towns.
Around 700 residents were evacuated late on Friday after a dam broke in the town of Wassenberg near Cologne, authorities said.
The Steinbachtal dam in western Germany remained at risk of breaching, authorities said after some 4,500 people were evacuated from homes downstream.
Steinmeier said it would take weeks before the full damage, expected to require several billions of euros in reconstruction funds, could be assessed.
In Belgium, the death toll rose to 27, according to the national crisis centre, which is coordinating the relief operation there.
It added that 103 people were "missing or unreachable". Some were likely unreachable because they could not recharge mobile phones or were in hospital without identity papers, the centre said.