Argentina is struggling with stubborn inflation and a tumbling peso currency, troubles that have driven down Macri's popularity in opinion polls and fueled speculation that Fernandez could make a successful comeback.
The decision comes after the crash as a week ago of a Boeing 737 MAX operated by Ethiopian Airlines that killed 157 people. Five months earlier, a Lion Air flight using the same model also crashed shortly after takeoff, killing 189 people.
Argentina will seek to reduce its fiscal deficit to 1.3 percent of gross domestic product in 2019, down from 2.2 percent previously. The deal calls for fiscal balance in 2020 and a fiscal surplus of 0.5 percent of GDP in 2020.