He said Kuwaiti authorities were running DNA tests to identify the 35 women and six children killed in the fire, which left many victims unrecognizable.
Authorities were investigating the cause and al-Mansouri said it could have been faulty electrical wiring, a problem with the equipment used to keep the wedding food buffet warm or the coals used for burning incense.
He added that the fire in al-Jahra, a tribal area west of the capital, was the worst he has seen in his almost four decades of service in this small oil-rich state and close U.S. ally.
Photographs of the scene show the tent was erected in an urban area. The interior was strewn with blackened debris, including the metal frames of chairs and tables, and burnt out air conditioners, a necessity in this hot country where night temperatures in the summer are often above 100 degrees (40 degrees Celsius).
It was not clear if the bride survived or how many were in the tent when it caught fire. Al-Mansouri said the structure was 13 yards (12 meters) long and could have housed up to 180 people.
Wedding parties are held separately for women and men, with children attending the women's event. The parties usually feature a catered buffet dinner as well as singing and dancing to Kuwaiti and Arabic music.
No alcohol is served in conservative Kuwait.
Al-Mansouri said 58 injured were still in hospitals, seven in serious condition with severe burns.
Events in tents should be licensed so that authorities approve the type of tent set up and ensure it has the necessary safety features, said the chief, adding that Saturday's event was not licensed.
The upholstery and the stuffing of the chairs used was also highly flammable, said al-Mansouri.
The Interior Ministry called on Kuwaitis to stop erecting tents in the middle of crowded neighborhoods and there has been talk of banning them altogether.
Tents are also used in election campaigns, but by permit only.
The government had opened a hot line and an information center for relatives of the victims, Kuwaiti state television said.
The country's ruler, Sheik Sabah Al Ahmed Al Sabah, extended condolences to the families of the victims and his office, according to the Kuwait News Agency.
He also announced that in sympathy with the victims and their families he would not be receiving well wishers as he traditionally does for the advent of the Muslim holy month of Ramadan which starts around Aug. 22.