Tanzanian President John Magufuli said on Monday he has signed into law new mining bills which require the government to own at least a 16 percent stake in mining projects.
The laws, which also increase royalties tax on gold and other minerals, were passed by parliament last week despite opposition from the mining industry body.
Magufuli reiterated on Monday that no new mining licenses would be issued until Tanzania "puts things in order" and that the government would review all existing mining licenses with foreign investors.
"We must benefit from our God-given minerals and that is why we must safeguard our natural resource wealth to ensure we do not end up with empty mining pits," Magufuli told a rally in his home village in Chato district, northwestern Tanzania.
The president has sent shock-waves through the mining community with a series of actions since his election in 2015, which he says are aimed at distributing revenue to the Tanzanian people.
The new mining laws, which were fast-tracked through parliament, raise royalties tax for gold, copper, silver and platinum exports to six percent from four percent.
They also give the government the right to tear up and renegotiate contracts for natural resources like gas or minerals, and remove the right to international arbitration.
"I would like to thank parliament for making the legislative changes. I signed the bills into law the same day Parliament concluded its session on July 5," Magufuli said.
Passage of the new legislation also followed months of wrangling between the government and the country's biggest gold miner, London-listed Acacia Mining Plc, over mining contracts after Magufuli decided in March to ban exports of gold and copper concentrates to push for the construction of a domestic mineral smelter.
Magufuli said on Monday that talks between Tanzania and Barrick Gold Corp., Acacia's majority owner, would begin in two days to try to resolve allegations of tax evasion against Acacia.
Tanzania accused Acacia of tax evasion in 2016 in a case that is ongoing.
Acacia, which denies all allegations, said on July 4 it was seeking an adjudicator to resolve its dispute with the Tanzanian government.
Tanzania is also pushing for the mandatory listing of mining companies on the Dar es Salaam Stock Exchange (DSE) by August as part of measures aimed at increasing transparency and spreading wealth from the country's natural resources.
Other major foreign-owned mining companies in Tanzania include AngloGold Ashanti and Petra Diamonds.