Under President Ibrahim Baré Maïnassara, who seized power in a January 1996 coup, Mayaki was named Deputy Minister for Cooperation, under the Minister of Foreign Affairs, André Salifou, on August 23, 1996. He was then named Minister of Foreign Affairs and Nigeriens Abroad in December 1996, in which position he served until being named Prime Minister in November 1997.
Fifth Republic
When President Maïnassara was overthrown and assassinated in April 1999, Mayaki was reappointed by Daouda Malam Wanké, the leader of the coup, to lead the country during the transition to new elections. He left office after the elections were held late in the year.
According to the Senate Select Committee on Intelligence report on prewar intelligence, Joe Wilson said that during Mayaki's time in office he was contacted by a businessman who asked him to meet with a delegation from Saddam Hussein's Iraq government, to discuss "expanding commercial relations." Mayaki interpreted that to mean they wanted to discuss the sale of yellowcake uranium, a natural resource of Niger, though upon meeting with the delegation, the subject of uranium never came up. None of the CIA, DIA, or INR analysts said this gave weight to claims that Iraq was trying to get uranium from Africa, and the Vice President was not briefed on the issue. There is no evidence that this claim about the meeting of an Iraqi delegation with Mayaki was used to bolster the case for war, or that it was in any way related to U.S. President George W. Bush's claim in the 2003 State of the Union address that "The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa," which was based on what the British says in the Butler Report is completely separate evidence.
In 2011, Mayaki was awarded medal of Officer in the National Order of Agricultural Merit, an order of merit established by the French government in 1883. On November 7, 2019 Ibrahim Assane Mayaki was awarded the title of "Grand Cordon of the Order of the Rising Sun" by Japanese Emperor Naruhito. This decoration, the highest distinction of the State of Japan, recognizes his contribution to the promotion of friendly relations between Japan, Niger and, more broadly, the African Union.
Publications
In addition to several academic articles, he published La Caravane Passe, a book relating his political experience.