However, Tajani has spoken to IMF Managing Director Kristalina Georgieva and urged her to show flexibility to stave off possible financial collapse.
Prime Minister Giorgia Meloni is also "working the phones", one official said, warning that Italy faced an "invasion of migrants" in the coming months if Tunisia did not get the money.
"Uncontrolled irregular migration can only be reduced by improving the conditions of security and economic stability," Tajani said, adding that Italy was looking to boost training opportunities for Tunisians as an alternative to migration.
Of the arrivals this year to Italy, the top country of origin is Ivory Coast (3,223), followed by Guinea (2,906).
"The stability and prosperity of Tunisia, with respect for fundamental rights and freedoms, are crucial for the stability of the entire Mediterranean region," Tajani said.