"The present difficulties ... well, I don't think it is really serious - it's an accident," he said.
"And the steps that we have taken in order to make sure that it doesn't happen, they are quite elaborate and I believe that it will be appreciated by all."
The government made similar promises after a garment factory fire five months ago that killed 112, saying it would inspect factories for safety and pull the licences of those that failed.
However, that plan has yet to be implemented.
Asked if he was worried that foreign retailers might pull orders from his country, Muhith said he wasn't: "These are individual cases of ... accidents. It happens everywhere."
Muhith has been criticised for insensitive comments in the past - even by his own party.
Last year when thousands of small investors lost their savings and poured into the streets seeking government intervention, Muhith said it wasn't responsible and the investors were at fault.
The official death toll from the April 24 collapse reached 531 on Saturday and was expected to climb, making it likely the worst-ever garment-factory accident.
At the site of the collapse, workers used cranes to remove concrete rubble to search for bodies. The official number of missing has been 149 since Wednesday, though unofficial estimates are higher.
A government investigator said on Friday that substandard building materials, combined with the vibration of the heavy machines used by the five garment factories inside the Rana Plaza building, led to the horrific collapse.
Mainuddin Khandkar, the head of a government committee investigating the disaster, said substandard rods, cement, bricks and other weak materials were used in the building's construction.
About 15 minutes before the collapse, the building was hit by a power blackout, so its heavy generators were turned on, shaking the weakened structure, he said.
"The vibration created by machines and generators operating in the five garment factories contributed first to the cracks and then the collapse," he said, adding a final report would be soon submitted to the government.
Police said on Friday that engineer Abdur Razzak Khan was arrested a day earlier on a charge of negligence.
Khan worked as a consultant to Rana Plaza owner Mohammed Sohel Rana when the illegal three-floor addition was made to the building, police said.
Authorities also suspended the mayor of Savar, Mohammad Refatullah, for alleged negligence, said Abu Alam, a top official of the local government ministry.
Alam said an official investigation had found that the mayor ignored rules in approving the design and layout of the doomed building.
- AP
