Magufuli launched several initiatives to clamp down on corruption since winning an election in November.
Businesses have long said corruption was a major obstacle to working in the east African nation and a deterrent to investment. Tanzania is ranked 117th out of 168 countries in Transparency International’s 2015 corruption perception index where No. 1 is least corrupt.
“The president’s instructions that all ministers who were yet to declare their assets and liabilities should do so before 6pm (on Saturday) has been implemented,” the prime minister’s office said in a statement. It said those who did not would be fired.
Earlier this week, a body that monitors civil servants said four senior ministers and one junior minister had yet to sign.
Cabinet ministers and other public officials are required by law to declare their assets and liabilities at the country’s ethics secretariat by Dec. 31 each year, but in the past this has often been ignored. The integrity pledge is new.
Magufuli, who took office late last year, has pledged to root out corruption and government inefficiency. He has sacked several senior officials, including the head of the government’s anti-graft body, the chief taxman, a senior rail official and the head of the country’s port authority.
Tanzania is one of Africa’s biggest per capita aid recipients, but payments have often been delayed because donors said they were concerned about corruption, poor governance and the slow pace of reforms.
In 2014, a group of donors withheld nearly $500 million in budget support to Tanzania over corruption allegations in the energy industry after a scandal led to the resignations of three cabinet ministers.