The Azzurri have won two matches in the Six Nations tournament for the first time this season and host Ireland on Saturday.
"I don't know if I can be there for Italy-Ireland, but I promise that in September I will go and see the Azzurri at the World Cup in France," Prodi said, according to the ANSA news agency.
In its last two games, Italy beat Scotland at Murrayfield for its first road victory in the Six Nations, then edged Wales 23-20 on Saturday with a late try by Mauro Bergamasco.
Prodi said he watched the game against Wales on TV.
"I got excited, and I was doing the play-by-play like a radio announcer. I had (undersecretary) Enrico Letta on the phone and he wanted me to tell him how the game was going, so I explained the final minutes to him in live time," Prodi said.
Italy coach Pierre Berbizier was moved by the meeting in the premier's office, reports AP.
"I'm French but it was an honor to be received by your premier, who is supporting us," Berbizier told local reporters.
The Chinese military believe that Beijing and Moscow must resist pressure from Washington together