Italian marines - Massimiliano Latorre and Salvatore Girone - were sent back to India on March 22 to be tried for allegedly killing two Indian fishermen, in a U-turn after Rome had said they would not return after being allowed to come home to vote.
The decision to hand them back, after a diplomatic tussle in which the Italian ambassador was blocked from leaving India, split the government and Foreign Minister Giulio Terzi resigned earlier this week saying his view that they should not be returned had not been listened to.
Di Paola criticised Terzi for quitting and said he would not abandon "the ship or the marines".
Defense Minister Giampaolo Di Paola was speaking at a ceremony in Naples honoring the 90th anniversary of the Italian airforce when his voice cracked and his eyes watered up, Italian news agency ANSA reported.
He denied media reports here that the marines had been unwilling to return to India for trial.
"It's not true that Salvatore and Massimiliano took five hours to agree with this decision. They were not just obeying orders, but also their sense of duty and responsibility. They honoured their word", Di Paola was quoted as saying by ANSA.
"They respected their uniform in spite of their pain, pushing back their own emotions and those of their families", the Minister added.
The Monti government returned Latorre and Girone after getting assurances they would not face the death penalty for allegedly shooting Indian fishermen Jelestine Valentine and Ajesh Binki while guarding the oil tanker Enrica Lexie.