Prime Minister Clement Mouamba's government had presented its resignation yesterday, said a statement from the president's office.
The announcement came two weeks after the ruling party's comfortable election win in legislative elections but as the country struggles to overcome an economic crisis.
In a speech Monday on the 57th anniversary of the country's independence, Sassou Nguesso acknowledged the problems facing the country.
"These difficulties started out as financial. Today they have spread into the economic and general areas," he added.
More From This Section
The IMF recently accused Brazzaville of having hidden part of its debt from the organisation by claiming it was 77 per cent of national output.
Part of the oil-rich country's troubles have been caused by the fall in the price of oil on world markets.
The country's opposition blamed the outgoing government for the crisis.
Jean Itadi, one of the leaders of the opposition, was holding a press conference as news broke of the government's resignation.